Fix loss of gdextension on editor startup

[Hilderin]

• Fixes extension_list.cfg in .godot folder is deleted when opening a project #97900
• Fixes Custom GDExtensiom MainLoop does not work if .godot is already generated #97962
• Fixes Android gdextension fails to load #98056
• Fixes Extension singleton not found when running project after exporting with another Godot instance #97735

The GDExtension files were not processed in EditorFileSystem::_first_scan_process_scripts following optimization in #95678.

Thanks to @NetroScript to pinpoint the problem and find the solution. This PR is based on it's suggested modifications. That's why I added him as Coauthor.

I think your approach to use ResourceLoader::get_recognized_extensions_for_type is the right one. It's sounds like a bug to me that the method returns .res and .tres for GDExtension. I'm not an expert of the GDExtensions but I'm pretty sure .res and .tres are not supported for GDExtensions. If you check into GDExtensionLibraryLoader::parse_gdextension_file, it only supports a ConfigFile format and not a resource file. It does not seems easy to modify ResourceLoader::get_recognized_extensions_for_type to not return .res and .tres for GDExtension and I'm worry about side effects so I think that excluding .res and .tres extensions in _first_scan_filesystem seems the right way to me.

Edited: Adding #97962 in the fixed issue list.
Edited: Adding #98056 in the fixed issue list.

[FireCatMagic]

This should also fix #97962

[NetroScript]

Thanks for the fast PR. When I checked it out I also found no way to exclude res and tres. As all resource loaders get iterated to find extensions the ResourceFormatLoaderBinary for example also is iterated, which returns true for all handled types (there in theory it would be possible to add an exclusion from my uneducated observations), which causes res to be added.

[Hilderin]

Exactly! We will see what reviewers think about that.

[TCROC]

This also fixes gdextensions not loading on android: #98056

[fire]

I think we should rename and attempt to modify ResourceLoader::get_recognized_extensions_for_type to not return .res and .tres for GDExtension

Or at least see that its too difficult

[KoBeWi]

The code seems fine.
This fixes a few GDExtension regressions, so it would be nice to get it merged soon.

It's sounds like a bug to me that the method returns .res and .tres for GDExtension.

It's not exactly a bug. ResourceFormatLoaderText/Binary handle any type of Resource (because you can save/load everything as .res or .tres), and that's where these extensions come from.

[dsnopek]

It's not exactly a bug. ResourceFormatLoaderText/Binary handle any type of Resource

I haven't tested it, but I don't think re-saving a .gdextension file as .tres/.res would result in a working GDExtension, because the GDExtension resource class doesn't keep all its data in registered properties. If there's a way to prevent re-saving as a .tres/.res we should probably do that - although, that's not in scope for this PR.

[KoBeWi]

It's similar issue to #34080

[dsnopek]

This fixes issue #97900 in my testing!

Skimming the code, it looks good to me, but I don't know EditorFileSystem as well as @Hilderin or @KoBeWi - I trust their judgement :-)

[Hilderin]

As suggested by @fire, I modified code to prevent ResourceLoader::get_recognized_extensions_for_type returning res and tres extensions for GDExtension. I little if added in ResourceFormatLoaderBinary::get_recognized_extensions_for_type and ResourceFormatLoaderText::get_recognized_extensions_for_type did the trick.

[Repiteo]

Thanks!