Blender Git Loki

Fix T59376: UV project modifier not working after modifiers that dont provide a UVMap

This was reported for remesh and skin modifiers.
These dont preserve UV layers (and probably cannot in a reasonable way),
so instead let the UV Project modifier create a new (equally named) UV
layer (as was suggested by @brecht in T59376).

Maniphest Tasks: T59376

Differential Revision: https://developer.blender.org/D10617