Convenience syntax for many

[epage]

In writing #1580 and considering #1408, I've been wondering how to better handle repetition. At the moment, my guiding thought for ´Parser` is it should only have helpers to operate on Output and not on Parsers.

A thought I had was could we and should we make parser * 5, parser * 1..5 work?

We could then extend that to #1508 and allow HEX_DIGIT * 4 to turn them into parsers.