Reuse table widget in picker

[sudormrfbin]

Continues #2814. This change reuses the table widget directly in the picker, finally allowing items to be formatted as columns 🎉. Column formatting can be done by implementing menu::Item::row() on the picker items.

Behavioral Changes

• There was a subtle bug in rendering the highlights for matching text which produced incorrect highlighting with multi byte characters. The algorithm to calculate highlights had to be re-written anyway to be injectable into a row of the table, and the issue was fixed along with this:

    The fuzzy matcher returns char indices of the choice that matched
    the pattern, while highlighting can only be done on whole graphemes.
    The earlier code assumed char indices == grapheme indices which
    broke highlighting with characters like å.
    
    This commit solves this issue by converting highlighting char indices
    to byte ranges, finding the grapheme which has this byte range as
    it's subrange, and then highlighting the whole grapheme.

Before	After

• Pickers that previously aligned items to the right (like the file picker which shows the end of the filename if the window is too narrow) cannot do so anymore; this will require a new align property on table cells.

Bugs

• I noticed problems with some columns not being displayed randomly when moving up and down the picker (with a modified column formatted version of the diagnostics picker). Requires proper investigation.

Future Work

• Use column formatting in buffer picker, symbol picker, etc.
• Add align property to table::Cell

[sudormrfbin]

The table column width calculation code has been updated to match the upstream implementation in the tui crate (specifically fdehau/tui-rs@a68e38e), and the random swallowing of columns have been fixed.

[gibbz00]

@sudormrfbin I'm working on a branch that aims to refine the keymap presentation in both the info boxes and the command palette. Wanted to see how the command palette could look with column formatting, so I've already started on an implementation for that hehe.

5f8ba8c

I will post the draft during the week, only marking it as a PR once this one gets merged. Feel free to use the code in the commit in the meanwhile (also in case mine doesn't go through), I'll just make sure to omit the commit from my draft if you do :)

[archseer]

Great work as always!

[archseer]

(oops)