Add a zoia grep/zoia search verb

[Infernio]

Has the advantage over grep/rg that it can parse the project and create plaintext representations to search.

Consider this Zoia text:

"That is *very* unfortunate", says Malcolm, fighting down the *sheer delight* that wants to take over his face at the news.

If I want to look for very unfortunate, then grep/rg will find nothing - I'd have to enter (and escape) the asterisk before 'unfortunate' for it to work. zoia grep, on the other hand, would have no problem:

$ zoia grep "very unfortunate"
src/work1/ch1/main.zoia:
  23: "That is *very* unfortunate", says Malcolm, fighting down the *sheer delight* that wants to take over his face at the news.

Not sure if I want grep and search to be synonyms or if search should maybe default to a literal search (i.e. no bothering with regexes)?