EditorProperty Copy value also to the clipboard

[kleonc]

"Copy Value" of property in the inspector was copying the value only within the context of the inspector, nothing was copied to the clipboard. See #66689 (comment). Now value.get_construct_string() is set to the clipboard.

• This seems to work nice with the non-Object built-in types, including Arrays or Dictionaries (nested too).
• Enum values are copied as the underlying value so e.g. 0 instead of PROCESS_MODE_INHERIT.
• Not too useful for Resources, e.g.:
  • copying Texture produces something like Resource("res://icon.svg"),
  • copying scene's ShaderMaterial subresource produces Object(ShaderMaterial,"resource_local_to_scene":false,"resource_name":"","shader":null,"script":null)

Not sure if Resources should be handled somehow differently or if it's fine as is.

[akien-mga]

Not too useful for Resources, e.g.:

• copying Texture produces something like Resource("res://icon.svg"),
• copying scene's ShaderMaterial subresource produces Object(ShaderMaterial,"resource_local_to_scene":false,"resource_name":"","shader":null,"script":null)

I wonder if we could copy the UID instead, or the scene SubResource path?

[KoBeWi]

I found the current separate clipboard convenient a couple of times, but this option is fine too (and seems to be expected by some users).

Not too useful for Resources

And for Nodes, which become null. Maybe we could just disable this for TYPE_OBJECT.