sanitize-filename terminal utility in bash

Convert spaces to underscores, trims punctuation parentheses etc and leading/ending whitespaces.

For GUI, it uses zenity.

Use

• Use as env NO_GUI=sth sanitize-filename [...] to disable GUI.
• Use as env verbose=true sanitize-filename [...] to enable verbose debugging messages.
• Use as env dry_run=true sanitize-filename [...] to not actually perform any filesystem operations.

Add to Thunar's context menu as an action

End result:

1. Open the custom actions menu.
   
2. Create a new action and set these values.