Introduce regex / wildcard matching into --filters flag

[liamcervante]

Similar to the go test -run command.

-run regexp
    Run only those tests, examples, and fuzz tests matching the regular
    expression. For tests, the regular expression is split by unbracketed
    slash (/) characters into a sequence of regular expressions, and each
    part of a test's identifier must match the corresponding element in
    the sequence, if any. Note that possible parents of matches are
    run too, so that -run=X/Y matches and runs and reports the result
    of all tests matching X, even those without sub-tests matching Y,
    because it must run them to look for those sub-tests.