Advanced duplicate detection and merging

Currently, the merge option pops up for rem with identical text as a little button inside the focused rem. I propose either a powerup or a separate window that would collect all plausible duplicates, separating full-text matches from front-only, as well as allowing a blacklist of rem that should not be treated as duplicates. Ideally, the search conditions could also be customised further, including fuzzy search and so on. See the Calibre Find Duplicates plugin for examples.

The advantages are fairly obvious: a top-down view of possible undesired duplicates allows to easily reconcile them, while a blacklist leaves homonyms alone.

Obliquely connected requests are: automatic linking of typed words to existing rem (https://feedback.remnote.com/b/New-Feature-Requests/p/rem-link-one-time-shortcut) and https://forum.remnote.io/t/automatic-detection-and-highlight-of-possible-reference-to-existing-rems-for-new-entries-to-kb/5860