[FEAT]: Add filter expression to review pane

[arent-groebner]

Is your feature request related to a problem? Please describe.

I've got a big vault (15K notes). The vault contains notes from all sorts of non related categories (say "Astronomy", "Biology", "Chemistry"). When using the review mechanism, the notes are currently presented regardless of their category.

When studying a specific Topic (say "Astronomy") I don't want notes from other categories (say "Biology") to show up. Thus, a mechanism is needed to focus on just a part of the vault. Otherwise Spaced Repetition is practically useless.

Describe the solution you'd like

An effective solution would be a filter field on top of the review pane. Ideally, the filter field would offer the same behaviour as the built-in search functionality (fulltext, path, file, tag,..). The filter would be applied to the list of notes currently given by the review mechanism ("post filter").

In my case, filtering just for the title would suffice, since my titles are prefixed by my categories (say "Astronomy - Sun", "Astronomy - Moon",..).

Additional context

If implementing the full search functionality as review filter is to hard, it would be great to have a simple short time solution, namely filtering just for titles.