Position prediction popover adjacent to edit if possible (#24750)

Also, place accept key binding indicator on right edge of popover to
avoid obscuring content above.

Release Notes:

- N/A

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>
Co-authored-by: rtfeldman <oss@rtfeldman.com>
Co-authored-by: Agus Zubiaga <hi@aguz.me>