Codechange: automatic adding of _t to (u)int types, and WChar to char32_t

for i in `find src -type f|grep -v 3rdparty/fmt|grep -v 3rdparty/catch2|grep -v 3rdparty/opengl|grep -v stdafx.h`; do sed 's/uint16& /uint16 \&/g;s/int8\([ >*),;[]\)/int8_t\1/g;s/int16\([ >*),;[]\)/int16_t\1/g;s/int32\([ >*),;[]\)/int32_t\1/g;s/int64\([ >*),;[]\)/int64_t\1/g;s/ uint32(/ uint32_t(/g;s/_uint8_t/_uint8/;s/Uint8_t/Uint8/;s/ft_int64_t/ft_int64/g;s/uint64$/uint64_t/;s/WChar/char32_t/g;s/char32_t char32_t/char32_t WChar/' -i $i; done

Change: [Network] Transfer command data as serialized byte stream without fixed structure.

The data will be transmitted as the length followed by the serialized data. This allows the command
data to be different for every command type in the future.

Feature: make "join game" button join the game, instead of first showing a lobby window (#9467)

Nobody really paid attention to the lobby window, and it completely
missed its purpose. Most people don't even wait for companies to
show up, but just hit "New Company".
This in turn means people create a lot of unneeded companies, while
they "just want to watch the game" or join another company.

Instead, "Join Game" now just joins the game as spectators.

Feature: join servers based on their invite code

This removes the need to know a server IP to join it. Invite codes
are small (~7 characters) indentifiers for servers, which can be
exchanged with other players to join the servers.

Change: groundwork to allow ServerAddress to use invite codes

Normally TCPConnecter will do a DNS resolving of the connection_string
and connect to it. But for SERVER_ADDRESS_INVITE_CODE this is different:
the Game Coordinator does the "resolving".

This means we need to allow TCPConnecter to not setup a connection
and allow it to be told when a connection has been setup by an external
(to TCPConnecter) part of the code. We do this by telling the (active)
socket for the connection.

This means the rest of the code doesn't need to know the TCPConnecter
is not doing a simple resolve+connect. The rest of the code only
cares the connection is established; not how it was established.

Fix: only query a manually added server if it isn't there yet

But always mark it as manually, no matter if it was there or not.

Feature: use Happy Eyeballs to make network connections (TCP-only) (#9199)

Hostnames like "content.openttd.org" resolve into multiple IPv4 and IPv6.
It is possible that either of the IPs is not working, either due to
a poorly configured OS (having IPv6 but no valid route), broken network
paths, or a service that is temporary unavailable.

Instead of trying the IPs one by one, waiting for a 3s timeout between
each, be a bit more like browsers, and stack attempts on top of each
other with slight delays. This is called Happy Eyebells.

Initially, try the first IPv6 address. If within 250ms there is no
connection yet, try the first IPv4 address. 250ms later, try the
second IPv6 address, etc, till all addresses are tried.

If any connection is created, abort all the other (pending) connections
and use the one that is created. If all fail 3s after the last connect(),
trigger a timeout for all.

Codechange: use connection_string in favour of NetworkAddress (#9197)

We now resolve the connection_string to a NetworkAddress in a much
later state. This means there are fewer places constructing a NetworkAddress.

The main benefit of this is in later PRs that introduce different types
of NetworkAddresses. Storing this in things like NetworkGameList is
rather complex, especially as NetworkAddress has to be mutable at all
times.

Additionally, the NetworkAddress is a complex object to store simple
information: how to connect to this server.

Change: use TCP for everything except for master-server and initial server scan (#9130)

This means that pressing Refresh button and adding servers manually
now uses TCP.

The master-server and initial scan are still UDP as they will be
replaced by Game Coordinator; no need to change this now.

If we query a server that is too old, show a proper warning to the
user informing him the server is too old.

Codechange: move all NetworkGameInfo related functions to a single file

It currently was a bit scattered over the place. Part of
NetworkGameInfo is also the GRF Identifiers that goes with it.

Remove: "language" field from server/client

The original idea was that people could find a server they could
talk in their native language on. This isn't really used in that
way. There are several reasons for removing this:

- the client also sends his "language" to the server, but nothing
is doing anything with this.
- flags are a bad way to represent languages, and over the years
we had several (rightfully) complaints about this.
- most servers have their language set to "All", and prefix the
servername with the language it is about. This is a much more
efficient way to do the same.

All in all, this feature should go back to the drawing board.
Maybe it could work in another form, but this form is not it.

Remove: ENABLE_NETWORK switch

This switch has been a pain for years. Often disabling broke
compilation, as no developer compiles OpenTTD without, neither do
any of our official binaries.

Additionaly, it has grown so hugely in our codebase, that it
clearly shows that the current solution was a poor one. 350+
instances of "#ifdef ENABLE_NETWORK" were in the code, of which
only ~30 in the networking code itself. The rest were all around
the code to do the right thing, from GUI to NewGRF.

A more proper solution would be to stub all the functions, and
make sure the rest of the code can simply assume network is
available. This was also partially done, and most variables were
correct if networking was disabled. Despite that, often the #ifdefs
were still used.

With the recent removal of DOS, there is also no platform anymore
which we support where networking isn't working out-of-the-box.

All in all, it is time to remove the ENABLE_NETWORK switch. No
replacement is planned, but if you feel we really need this option,
we welcome any Pull Request which implements this in a way that
doesn't crawl through the code like this diff shows we used to.

(svn r17617) -Codechange: make the server side packet handling be more like the client side's handling, i.e. return the connection status
-Fix: do not do invalid reads when a packet handling function closed a connection

(svn r13369) -Codechange: remove duplication of network configuration settings between NetworkSettings and NetworkGameInfo.
-Fix: failure of changing the server password during games because the password wasn't duplicated properly.