Allow running arbitrary actions over bookmarks

[fmartingr]

We dont have a way of running some actions over bookmarks at the moment. We can update the boomkark cache in several ways but we don't have a way of updating the readable version, deleting some of the local content and probably other.

Using this issue as a point of discussion for the work that may be required in order to achieve two singular actions:

• Delete bookmark archive
• Update bookmark readable version

This issue not only covers the backend works (which should be fairly easy, but we should refactor it into Domains), but also how it may look in the UI and if we should allow CLI options for all of this.

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Original issue description: Right now if we add a bookmark with automatic archival from Youtube, a useless archive is made with no means of removing it from Shiori itself, we would need to remove it from the filesystem manually. Provide an option to remove Archive, Thumbnails and Contents from bookmarks.