Ensures all resource types support UIDs in a project.
This is required to fix:
* Scripts and many other resource types can't be referenced by UID and when refactored the references are lost.
* Path export properties can't use UID for unsupported types.
* Refactoring problems when files are moved outside the editor (this PR effectively fixes it).
* Editor properly refreshing paths if they changed externally while opened (as example, git update).
This needs to be addressed in a subsequent PR, but this one effectively sets the prerequisites.
Resource types that do not support UID will get a .uid file appended to them (this includes .gd, .gdshader, .gdextension, etc. files).
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