Add: [NewGRF] Map seed as global variable.

This is useful to provide a feature-agnostic, stable random value that differs between games.
One of the possible uses is to e.g. use it to create pseudo-random regions for towns or industries.

Update: Translations from eints
latvian: 4 changes by lexuslatvia

Update: Translations from eints
finnish: 2 changes by RedJimi

Update: Translations from eints
chinese (traditional): 3 changes by benny30111
galician: 9 changes by mgtrad, 1 change by NicoSGF64
indonesian: 14 changes by bsuseno

Fix: Original music playback rate was slightly too fast

Found a new tempo value experimentally. The new value gives a timing error of less than 0.01 second per minute.

Update: Translations from eints
japanese: 9 changes by Azusa257

Fix #9811, 9156d7b: Use the NewGRF-defined vehicle center when dragging ships and aircraft. (#9812)

The alignment using the total-width of the vehicle-chain was meant for articulated trains and road vehicles only.

Update: Translations from eints
turkish: 1 change by AlphenLLC

Update: Translations from eints
korean: 1 change by telk5093
turkish: 5 changes by AlphenLLC

Feature: Add/extend console commands to enable screenshot automation (#9771)

* Add: `zoomto` console command for main viewport

Similar in spirit to `scrollto`, `zoomto` takes an absolute zoom level
from the user and sets the main viewport to that level while respecting
both the absolute minimum and maximum zoom levels supported by the game
and any limitations imposed by the local client settings.

* Add: optional `instant` flag for `scrollto` command

Using this flag has two effects:

- if the user has smooth scrolling enabled, the scroll action will take
place as if it were not enabled
- the viewport is redrawn immediately, so any successive `screenshot`
command will actually work correctly

The original positional arguments are processed like same before.

Update: Translations from eints
belarusian: 35 changes by KorneySan

Update: Translations from eints
thai: 122 changes by phetoffux

Update: Translations from eints
thai: 8 changes by phetoffux

Update: Translations from eints
swedish: 15 changes by joeax910
slovak: 5 changes by FuryPapaya
thai: 15 changes by phetoffux

Update: Translations from eints
korean: 2 changes by telk5093
slovak: 14 changes by FuryPapaya
thai: 107 changes by phetoffux

Update: Translations from eints
italian: 61 changes by denialmac

Update: Translations from eints
irish: 2 changes by temuchie

Update: Translations from eints
tamil: 24 changes by Aswn

Update: Translations from eints
tamil: 19 changes by Aswn

Update: Translations from eints
vietnamese: 28 changes by chupper100

Update: Translations from eints
croatian: 67 changes by srekoslav

Update: Translations from eints
croatian: 6 changes by srekoslav
thai: 2 changes by sanotti

Update: Translations from eints
norwegian (bokmal): 2 changes by tmn

Update: Translations from eints
romanian: 18 changes by Gisterecis

Fix: [CMake] openttd.32.bmp wasn't installed but used by SDL (#9772)

This file is used to set the SDL application icon, but it was no longer
installed since the switch to CMake.

Change: [OSX] Allow touchbar usage on all supported OS versions.

Touchbar support was introduced in 10.12.2. There's no need to limit
support to 10.15+, as the convenience class NSButtonTouchBarItem is
easily replicated.

Update: Translations from eints
chinese (traditional): 25 changes by Tetrapod1206
italian: 12 changes by federico1564S

Update: Translations from eints
portuguese (brazilian): 2 changes by Vimerum

Update: Translations from eints
czech: 6 changes by vladoschreiner
hungarian: 5 changes by pnpBrumi

Doc: use only double quotes for cmake command line example in COMPILING.md (#9758)

While powershell happily accepts single quotes, it's not the case for cmd.

Update: Translations from eints
norwegian (bokmal): 4 changes by Anolitt

Fix #9756: Network command unpack proc was not generated in all cases.

The case where the callback proc takes all command results but not any of
the command parameters was not handled properly.

Change: [Admin] Bump admin port protocol due to command changes.

docs/admin_network.md promised that information in an admin packet
is never removed. It does allow the possibility of using a new packet type
for changed data in combination with a bump of the admin port version.

As the recent command handling changes modified the contents of
ADMIN_PACKET_SERVER_CMD_LOGGING, do exactly that.

Codechange: Don't generate CommandPacket unpack functions for invalid cmd/callback combinations.

If the arguments of the callback proc don't match with the command parameters,
we can't do the proper command execution anyway. As such, don't even generate
an unpack function in the first place, saving a bit of unnecessary code bloat.

Validate on receive that the cmd/callback combination is supported, rejecting
clients that try to send invalid values.

Codechange: Add DoCommand::Post specialization for commands that take no TileIndex.

This adds a new Post overloads that still take a TileIndex which
is used to place any error windows or text effects.

Codechange: Template DoCommandP to automagically reflect the parameters of the command proc.

When finished, this will allow each command handler to take individually
different parameters, obliviating the need for bit-packing.

Codechange: Template DoCommand to automagically reflect the parameters of the command proc.

When finished, this will allow each command handler to take individually
different parameters, obliviating the need for bit-packing.

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.

Codechange: Make TileIndex a "strong" typedef to give it a distinct type.

This is accomplished by changing it to a single member struct with the
appropriate operator overloads to make it all work with not too much
source modifications.