Enforce that custom nodes and resources created via the "Create New Node" dialog, should permanently retain their original type (script). This means:
- Type continuity: It should be impossible for the user to (accidentally) clear the original script of a custom node that was created via the "Create New Node" dialog.
- Extensibility: The user should be able to extend custom types as usual (create a script that inherits the original type and replace the original script of that node with his own). However, if he then clears his extension-script from that node later on, the custom type should revert to its original script instead of becoming a non-scripted type.
This helps with confusion over how selecting a key with a duplicate
value won't be selected as only the first entry with a particular value will
be selected.
This change introduces a new theme configuration struct to be
passed to the aforementioned routines to better control reuse
of styles and definitions in the generator.
Everything not passed and not explicitly shared is scoped so it
is not automatically accessible throughout the routine. This
should ensure that the decision to share styles is a conscious one.
In the future we will try to reduce the number of unique definitions
and share most of it. This PR is a stepping stone on this path.
This also puts the effort into separating redefinitions of
default theme items vs custom types introduced only by the editor.
In a few cases where editor-specific definitions need to reference
default definitions we simply fetch them from the theme. It's not
ideal and hides the dependency a bit, but hopefully these cases
will be abstracted properly in due time.
This change introduces a new EditorThemeManager class
to abstract theme generatio and its subroutines.
Logic related to EditorTheme, EditorColorMap, and editor
icons has been extracted into their respective files with
includes cleaned up.
All related files have been moved to a separate folder to
better scope them in the project. This includes relevant
generated files as well.
