[Server Request]: Generic Steam gameserver

### Game server

variable

### Linux support

- [X] Yes

### Steam

Yes

### Steam appid

variable

### Guides

An idea, for the numerous steam games that aren't supported yet or won't be (unpopular, or need for wine/proton): A generic Steam gameserver install would allow users to essentially install whatever steam server they want, and manage/update it with LGSM.
This can be provided as-is, with no guarantee that it will work, placing most of the configuration on the user, but still allowing them to use lgsm commands for start/stop/update/validate/console keeping it normalized between multiple gameservers

With it, the configuration settings would be limited. Settings that would normally not be touched would become primary configurations.
For example, appid, executabledir, executable, preexecutable, startparameters, consoleinteractive, consoleverbose, stopmode would all be primary configurations in _default.cfg, querymode would probably just be session based for simplicity.
Possibly offering a custom stopmode command for some servers that do something particularly strange. essentially a stopcommand variable that allows a custom string to be sent to the server's console, rather than just "stop"/"quit"/etc,
It would be on the user to configure these to what they need to be for the server.
Almost all of this is already present in every steam server install, with the exception of preexecutable that only shows up on some servers (like minecraft for the java executable), but it would just be a very barebones install with no "fix_server.sh" module.

And as much as it has ever been avoided, adding a "windows version" variable that causes the steamcmd install/verify to use the flag to force windows version (steamcmd +@sSteamCmdForcePlatformType windows +login anonymous ...) wouldn't be so bad in a "as-is" generic steam game install. it would still be entirely on the LGSM user to overcome any issues they run into, but with the freedom to do what they wanted.

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct