console.lua: implement exact matching

Allow matching items exactly instead of fuzzily when prefixing the
search with ' (like in fzf) or with
--script-opt=console-exact_match=yes.

This is mainly useful to filter history entries chronologically.

You can also specify multiple search terms delimited by spaces. But '
makes every term an exact match, unlike fzf where you need to place it
before every word, since we can't hook into fzy's algorithm.

Closes #14587.