feature: BEAMMP_PROVIDER_DISABLE_MP_SET environment variable

[TechStreetDev]

This pull request adds BEAMMP_PROVIDER_DISABLE_MP_SET variable (true/false/1/0) to disable MP::Set for providers.

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[WiserTixx]

Could the lua state name/plugin name be included instead of "A script"?
and could you use the format version of the log functions to make the code cleaner?
Example:

BeamMP-Server/src/LuaAPI.cpp

Line 157 in 9fa9974

beammp_lua_errorf("Respond failed, dropping client {}", PlayerID);

[TechStreetDev]

Could the lua state name/plugin name be included instead of "A script"?

I could not figure out how to do this, and there is no other method which does this as far as I can tell (to copy from)

[WiserTixx]

I suppose you could move the check (and error message) to

BeamMP-Server/src/TLuaEngine.cpp

Line 921 in 6f196ac

MPTable.set_function("Set", &LuaAPI::MP::Set);

because the state name is available in that scope.
Something like:

if (mDisableMPSet) {
   MP.set_function("Set", [this](int ConfigID, sol::object NewValue){
      beammp_lua_errorf("A script ({}) tried to call MP.Set to change setting '{}' but this was blocked by your server provider.", StateId, GetSettingName(ConfigID));
   });
} else {
   MPTable.set_function("Set", &LuaAPI::MP::Set);
}