Make deletion of all photos more robust, and a few other contributions merged

[lcorbasson]

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This PR builds upon previous contributions:

• #43 by @ss23,
• #53 by @gpmidi,

and improves them a bit by:

• allowing the user to select how many items should be deleted and which kind of items through the called function's arguments,
• fixing the issue with huge sets (thousands of pictures) where the wait time for new checkboxes to re-appear can be quite long, and you'll need to sleep and retry.

This still needs some formatting and documentation to be improved.

[lcorbasson]

Note that this was successfully tested on a set of 96,000 photos using Chromium 114 on Debian GNU/Linux "bookworm".

[mrishab]

Please resolve conflicts and reduce diff for comprehension