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

Codechange: Use std::optional for GRFConfig::GRFError (#11066)

This changes the semantics from "object pointer ownership" to "optional object", and simplifies copies.

Codechange: Use std::array for GRF(File|Config) parameters.

This simplifies comparison, copying and assignment operations.

Change: include fmt.h C++ headers in stdafx.h

This to prevent compilation issues between runs with and without precompiled
headers. Also remove the headers from the rest of the code base as they are
not needed there anymore, although they do relatively little harm.

Remove: the concept of UnknownGRFs

These were filled with "<Unknown>" (before 8a2da49) and later their name would get filled via UDP requests to the server. These UDP packets do not exist anymore, so they will always remain "<Unknown>".
Remove that logic and just use the generic translated error GRF UNKNOWN string instead.

Change: mark copy-assignment as deleted for classes with a copy-constructor that is not trivial

This to prevent the default copy-assignment getting used when during the assignment also some other memory needs to be allocated as that would otherwise be freed.

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 r19251) -Codechange: add a contructor to GRFError and use it to allocating errors more uniform.
-Fix: some grf error messages didn't free the previous error messages, creating a memory leak

(svn r11433) -Fix: starting OpenTTD with DOS files made it look weird out of the box.
-Change: make extra sprites (the ones not in the TTD GRFs) replaceable using Action 5.
-Feature: make replacing contiguous subsets of sprites in for some types possible in Action 5.
Note to GRF authors: when you replaced OpenTTD sprites that are not from the TTD GRF files using Action A, your GRF will not have the intended result anymore as the sprite numbers have changed. You should replace the Action A with an Action 5 from now on.

(svn r10114) -Fix: Only load newgrf error messages if the language matches the current
language. Since only one error can be loaded anyway, if the language didn't
match you'd get "Undefined string". Also since we're only loading one language
there's no need to use AddGRFString any more.

(svn r9560) -Codechange: add support for multiple 'base' directories for newgrf searching.
-Codechange: do not add duplicate files to the newgrf list.

(svn r9031) -Codechange: Introduce grfconfig->status, and use it for states that are
mutually exclusive. At the same time, add an INITIALISED state which makes it
possible to check if a grf is not yet active but will be later on during the
GLS_ACTIVATION loading stage.

(svn r8838) -Feature: Show newgrf error messages loaded in Action B in the newgrf gui
window. GRFs with an error have a warning symbol shown before the name.