[Docs] Fix GetUnitWeaponState

Format it into something more usable for the emmylua annotations and docgen. Source: https://github.com/beyond-all-reason/spring/blob/3003a30f988ce7c13c0060f108a69efd383996da/rts/Lua/LuaSyncedRead.cpp#L5112-L5143

In particular use either an `alias` for the param argument or some way to indicate its a name of a field in the `WeaponState` class (as long as that's true, engine might be quirky sometimes).

Make sure to check the list of params is up-to-date and describe better or add when necessary

Read the GetUnitWeaponState implementation in rts/Lua/LuaSyncedRead.cpp at lines 5112-5143, then locate its emmylua annotation and docgen representation. Compare the documented parameter list with the implementation and WeaponState fields, and finish when the parameter naming or aliasing and descriptions are usable and up to date.

Written by the indexing model from the issue text.