[TRACKER] Make snapping, grid and transformation more consistent across 2D and 3D

[MarcusElg]

This pr tracks enchancements to implement regarding transformation, snapping and grids for both myself and others to implement.

3d features to port to 2d:

• Scale snap (pr: Added snapping for scaling in 2D editor godot#33182)
• Movement handles (pr: Added movement handles to 2D godot#33451)
• Transformation message, the little message in the bottom left corner that says for example: Translating: (0, 1, 0)
• Transform dialog, allow you to quickly move, rotate or scale the object with numbers instead of handles/drag (W.I.P pr: Port transformation window to 2D godot#37828)

2d enhancements:

• Make the snap relative option affect rotation (pr: Made snap relative work on rotation as well godot#36887)
• Make the snap relative option affect scaling (pr: Relative scale snapping 2D godot#37823)

2d features to port to 3d:

• Infinite grids (pr: Dynamic infinite 3D grid godot#28289)
• Configurable grid, spacing and offset
• Relative snap, enabled by default to keep current behaviour but adds the option for absolute snapping aka snapping to grid for movement, snapping the result for rotateting/scaling
• Rotation snap offset

Let me know what you think of these suggestions and if you would like to add any more and I'll try to implement those that the community likes. Thanks!

[Seel]

I'd love configurable grid and absolute snapping.

[Calinou]

[ ] Configurable grid, spacing and offset

This is already available in 3D, but it's in the Editor Settings. There are also less options available (no offset, no non-square grid). We should move this to a per-scene setting (complemented with a default value for new scenes in the Project Settings). We should also add that project setting for the 2D editor.

[MarcusElg]

I'd love configurable grid and absolute snapping.

I'm gonna implement more stuff once 3.2 is out. Adding things now will just create conflicts :P

[MarcusElg]

[ ] Configurable grid, spacing and offset

This is already available in 3D, but it's in the Editor Settings. There are also less options available (no offset, no non-square grid). We should move this to a per-scene setting (complemented with a default value for new scenes in the Project Settings). We should also add that project setting for the 2D editor.

I had no idea those settings existed for 3d. Defiently felt like the wrong place. 2D already have those features though,

[fire]

Is it possible to separate the proposals? Separate proposals makes voting and explaining uses for each proposal easier.