Improve Bookmark syncing

[0x-r4bbit]

Syncing bookmarks today works as follows:

• Bookmarks are really only synced when paring a device and hitting the "sync now" button (this syncs all things that can be synced)
• They are not synced in "real-time" when, for example, adding a new bookmark (this is easily fixed and already done on my machine)
• While adding bookmarks and syncing them is easy, it's a bit harder to account for deleting, then syncing bookmarks (this will be done in a separate issue)

This task is about ensuring that syncing bookmarks is done in real-time, when adding/deleting bookmarks, not just when syncing devices.

The deleting scenario for now will be done by simply setting the existing removed flag to true in the bookmarks table which is then synced. UIs will then have to check for removed to figure out whether or not they want to display bookmarks

This also means that bookmarks are never really deleted, this will be tackled by a garbage collection mechanism, described in this issue: https://github.com/status-im/status-go/issues/2705

[0x-r4bbit]

This has landed as of https://github.com/status-im/status-go/issues/2704