add action to tokenize input

[lytex]

The idea is to tokenize the input in live grep to allow for fuzzy-like search. For example a b c is turned into:

b.*c.*a|c.*b.*a|c.*a.*b|a.*c.*b|b.*a.*c|a.*b.*c

The prompt is split by spaces to build a regular expression with al the permutations of that token.

This is a draft, the code is working but I have a couple of things I want to finish:

1. Remove duplicate permutations
2. Interpret two spaces or more as a literal space

Any suggestions are welcome!

[lytex]

Removal of duplicate permutations implemented

[lytex]

Now two or more whitespaces get treated as an literal space.

A nice thing to have would be to revert back to pre-tokenized string when you apply the action on an already tokenized string.
The process of generating all the permutations does not preserve the order of the tokens, though, in this PR I won't be looking into that.