Vulkan: LightmapGI's bake() function is not exposed to scripting (unlike BakedLightmap in 3.x)

[Calinou]

Godot version

4.0.alpha (fb28025)

System information

Fedora 34, GeForce GTX 1080 (NVIDIA 495.46)

Issue description

LightmapGI's bake() function is not exposed to scripting (unlike BakedLightmap in 3.x).

Exposing bake() is useful for editor plugins that need to perform lightmap baking in an automatic manner, without relying on the BakedLightmap node currently being selected by the user.

Note that bake() will still not work in exported projects, as lightmapping and automatic UV unwrapping (xatlas) functionality is only available in the editor to decrease binary size. bake() will only work in projects run from the editor, as well as the editor itself.

I've tried to do this here, but I can't get environment lighting to show up when baking lightmaps by calling bake() in the editor on scene load: https://github.com/Calinou/godot/tree/lightmapgi-expose-baking
Older branch (predates multiple image atlases and many other LightmapGI changes): https://github.com/Calinou/godot/tree/lightmapgi-expose-bake-method

This may not be an issue we may be able to work around internally, but I want to know if manual baking after the scene has loaded works properly (I haven't been able to test this yet). Either way, we should document that particular quirk of the bake() method.

Steps to reproduce

• Look at the LightmapGI class documentation.
• Notice there is no bake() method exposed to scripting.

Minimal reproduction project

Testing project for the above linked branch: test_lightmapgi_bake_method.zip

[verypleasentusername]

Also would be really handy to make SDK's like map tools and if a tutorial on how to make bake() function exposed in local repo was made.