[FIX][ENH] Tiki API: Fix file upload/update issues

This MR should:

1. Fix unexpected results with upload and update files

   Issue on updating file : {"code":406,"errortitle":"File could not be uploaded: File empty","message":"File could not be uploaded: File empty"}

2. Fix the default galleryId when trying to create or update a gallery

3. Enhance file update endpoint naming structure from galleries/{galleryId} to galleries/{galleryId}/update

4. Fix the issue related to the file categorization (When a file is updated, the existing categorizations are lost)

5. Enhance feedback messages of actions move and remove gallery

6. Enhance the Tiki API file gallery endpoints documentation

Related task: https://avan.tech/item98647