Documentation and translations folder restructuring

[madmiraal]

This PR performs some needed housekeeping around documentation and translations to make things easier to find and understand:

• Renames the misc folder to tools.
• Moves the docs/tools scripts to the tools/scripts folder.
• Moves the docs/translations/extract.py script to the tools/scripts folder and renames it extract_api_strings.py.
• Moves the editor/translations/extract.py script to the tools/scripts folder and renames it extract_editor_strings.py.
• Moves the docs/translations folder to the project root.
• Moves the API XML files to the docs folder and removes the classes folder.

[DanielaOrtner]

Thank you for the housekeeping! New contributors will appreciate it as much as I do :)