Palette search cannot find sharp or flat key signatures typed as "F#" or "Bb"

Your idea

Let palette search accept the accidentals that are actually on a keyboard: # for ♯ and b for ♭, plus the spelled out words "sharp" and "flat".

Searching for F#, F sharp, Bb or B flat should find the corresponding key signatures, in addition to the existing behaviour of matching F♯ and B♭ literally.

Problem to be solved

Palette item names contain the real accidental signs — ♯ (U+266F) and ♭ (U+266D) — for example F♯ major / D♯ minor and B♭ major / G minor. Palette search does a plain substring match against those names, so none of the ways a user can actually type an accidental match anything:

• Searching F# → no results
• Searching F sharp → no results
• Searching Bb → no results
• Searching B flat → no results

The only search that works is a bare F, which returns every palette item containing the letter F, leaving the user to pick the right key signature out of the results by eye.

Neither ♯ nor ♭ is available on a standard keyboard layout, so at the moment there is no practical way to search for a specific sharp or flat key signature.

This affects every palette item whose name contains an accidental sign, most visibly the 14 sharp and flat key signatures.

Prior art

Nothing specific; this is the convention musicians already use when typing key and chord names in plain text (F#, Bb), and MuseScore itself accepts # and b when typing chord symbols.

Additional context

I have a fix for this and will open a PR referencing this issue.

No file or test is named in the issue. Locate the palette search substring matching and the palette item name construction, then check how accidental signs are represented. Done means searches for F#, F sharp, Bb, and B flat find the same key signatures as F♯ and B♭ without removing the existing literal matching.