Implement link-hint filtering ala Vimium

[kruecab]

Vimium has a feature called "link-hint filtering" which would be great to have in Vimari. The functionality is that after activating link hints, any typing done filters the active links to only those with matching text. For instance, on the GitHub page, you could press f to show link-hints, then type its and the only link remaining active would be "Issues" - pressing enter would activate that link. In cases where multiple links would match, the hints are re-numbered to only include those matching the filter.

This is the primary way I use Vimium link-hints and would be a great function for Vimari.

Thanks!