New Lua constants (#3022)

[TracerDS]

This PR is a direct response to the #3022 feature which adds new global variable: constants and assigns new fields to it:

• ElementType
• TriggerPriority
• DebugMessageLevels
• KeyState
• KeyNames
• ControlNames
• AnimationBlocks
• BodyPartName
• ClothesType
• Weather
• PedStats
• PedWalkingStyle
• PedFightingStyle
• HudComponents
• BlipIcons
• MarkerTypes
• PickupTypes
• ModelPickupTypes
• VehicleLights
• VehicleLightState
• VehicleDoorType
• VehicleDoorState
• VehicleLightOverride
• CarPanels
• PlanePanels
• VehiclePanelState
• VehicleWheelState
• VehicleSeat
• TrafficLightState
• WeaponSlot
• WeaponSkillLevel
• WeaponSkillName
• WeaponProperties

[tederis]

I think that the length of these constants makes them cumbersome and difficult to use. I doubt that long constructions like constants.VehicleLightOverride.Disable can be usefull. I would suggest to make them shorter.

[tederis]

In addition, I would suggest to make the table read-only.

[CrosRoad95]

Fine for me, just maybe other people may have concern about names, but apart of that it is good to go

[Pirulax]

Also, whats the point of not directly assigning the values to constants.* but instead making a local var first?
If there's no good reason, then we should just assign it directly [this also reduces the chance of interfering with existing scripts]

Also, there's a chance that some scripts might break if these constants are loaded into every script, we should have a meta.xml toggle for it, that toggles this feature per-resource [as theres one LuaVM per resource]

Also... I'm not sure if constants is the solution.
Perhaps we should just push them into the global namespace? [Like KeyStates.Up rather than constants.KeyStates.up.]
[I'm sure some people would prefer the one over the other]

And, as @tederis noted, making the tables read only might be useful [though Lua is somewhat limited in that regard]

[Pirulax]

Also something I just realized, these constants are pretty useless on their own.
There should be a way to convert to/from name/value.
Given:

local MyEnum = {
    First = 1
}

MyEnum['First'] should return 1. MyEnuim(1) should return First
This is similar to how Python work (Though Python returns special EnumValue objects that we can't afford in terms of performance, so we're going with the simpler solution here).

[TracerDS]

I think that the length of these constants makes them cumbersome and difficult to use. I doubt that long constructions like constants.VehicleLightOverride.Disable can be usefull. I would suggest to make them shorter.

What would we rename them to? 🤔

Also something I just realized, these constants are pretty useless on their own. There should be a way to convert to/from name/value. Given:

local MyEnum = {
    First = 1
}

MyEnum['First'] should return 1. MyEnuim(1) should return First This is similar to how Python work (Though Python returns special EnumValue objects that we can't afford in terms of performance, so we're going with the simpler solution here).

Implemented. Thanks for the suggestion ❤