Remove cruft from unit_buildmenu_config.lua.

[rhys-vdw]

Work done

Remove cruft and unused/uninitialized fields from luaui\configs\unit_buildmenu_config.lua.

Each change is made in its own commit for ease of review.

This was all discovered while adding type annotations, but the PR was rejected for including both doc comments and cleanup. The docs are added separately in #3936 as per @WatchTheFort's request.

Test steps

No functional changes

[saurtron]

Looks fine, while doing this you could also rationalize usage of showWaterUnits inside

Beyond-All-Reason/luaui/Widgets/gui_buildmenu.lua

Lines 218 to 221 in 4801b4c

	local showWaterUnits = false
	-- make them a disabled unit (instead of removing it entirely)
	if not showWaterUnits then
	units.restrictWaterUnits(true)

and

Beyond-All-Reason/luaui/Widgets/gui_gridmenu.lua

Lines 295 to 296 in 4801b4c

	local showWaterUnits = false
	units.restrictWaterUnits(true)

the first one is checking the value just after setting it to false.

[rhys-vdw]

Looks fine, while doing this you could also rationalize usage of showWaterUnits[...]

Yes, I saw that. I've found strange stuff like that in most files I've looked at. There's really no end to it. It's much easier to clean up when adding types because you get all the static analysis and highlights. I might do that file in a later PR.

For now I'd just like to get these merged.

[saurtron]

Looks fine, while doing this you could also rationalize usage of showWaterUnits[...]

Yes, I saw that. I've found strange stuff like that in most files I've looked at. There's really no end to it. It's much easier to clean up when adding types because you get all the static analysis and highlights. I might do that file in a later PR.

For now I'd just like to get these merged.

Imo since all of that looks like cleanup from the same original changes, they should be fixed in one go, but ok, your call :D.