EditorExportPlugin: Call _export_file for all resource types

[allenwp]

• Alternate fix to EditorExportPlugin._export_file is not called for many file types #67844 that calls _export_file for all resource types instead of implementing skip() for customize functions.
• This reverts the other previous fix, Allow skipping imported resource files from export #90365.
• Fixes EditorExportPlugin: Skipping a scene in _customize_scene gives error message #93823.
• Fixes EditorExportPlugin: Error when customizing "Keep File" resources #93825.
• Also fixes an issue that I suspect might exist where progress bars during export were incorrect due to imported files in the project that are configured as "Keep" or "Skip".

If this PR is merged, it supersedes #93820 because that PR is based on the other previous fix that is reverted by this PR.

I'm currently keeping this in draft with separate commits for the purpose of review. I can switch this over to a final pull request and squash the commits into one when others have had a moment to look at the changes. (Or leave some as separate, like the revert for example. Not sure what the preferred practice would be.)

[allenwp]

I've tested this with all the scenarios I can think of... It seems that remapping imported resources in the _export_file function works as expected (the same as it works for non-imported resources). It's not a use case that I expect people will want because the file you can remap to won't be imported, so I've added a note about exactly that in the documentation.

Testing is very welcome, of course!

[AThousandShips]

Has #90365 really been reverted? Can you link the PR reverting it? It hasn't been marked as reverted or linked in any revert PR

Edit: Or do you mean that this reverts that PR?

[allenwp]

Has #90365 really been reverted? Can you link the PR reverting it? It hasn't been marked as reverted or linked in any revert PR

Edit: Or do you mean that this reverts that PR?

Yes, I meant that this PR reverts that other PR. I’ve updated the PR comment to have more clear wording about this.

[KoBeWi]

I did some testing and the files are correctly skipped or included. Could be nice to test some plugins that use customization (I don't have one).

[allenwp]

I've left the commit that reverts the 4.3 beta 2 approach as a separate commit. Please let me know if I should squash this to be a part of my commit or if it would be better for a maintainer to revert it separate from my PR (not sure what the best practice is for Godot).

[akien-mga]

Thanks!