Removes some unnecessary includes from `editor_node.h`, and instead add
those where they're used.
Removes unnecessary `editor_node.h` includes in various editor classes.
Renames `dynamicfont` to `dynamic_font` in a couple files.
Misc cleanup while jumping through that rabbit hole.
-Allows displaying custom options for specific file format variants
-Added support for scene format import to retrieve custom options
This PR is necessary for #54886 to be implemented properly.
* Added a new macro SNAME() that constructs and caches a local stringname.
* Subsequent usages use the cached version.
* Since these use a global static variable, a second refcounter of static usages need to be kept for cleanup time.
* Replaced all theme usages by this new macro.
* Replace all signal emission usages by this new macro.
* Replace all call_deferred usages by this new macro.
This is part of ongoing work to optimize GUI and the editor.
