Support regex literals as functions

[tommy]

Regex literals can be used in places where functions or lambdas can be used. For example:

"123" ~> /([0-9]+)/ 

evaluates to

{
  "match": "123",
  "start": 0,
  "end": 3,
  "groups": [
    "123"
  ],
  "next": "<native function>#0"
}

Where the result of invoking the .next() function of this object returns the next match in the input string. This is similar to a lazy version of the $match function.

See: https://docs.jsonata.org/regex#generic-matchers