(PDB-798) Add capability to use regexp when querying fact-nodes path types

This adds the new operator ~> which is a path regexp operator that only works
against the `path` type. It works by internally converting the array of
regular expressions into a single regular expression for querying
fact paths.

Signed-off-by: Ken Barber <ken@bob.sh>
I think the main value is in the double asterisk support for *> ... you raise a good design point though. Adding ** wouldn't be hard.