Add missing tests for selector regexp matching (#16204)
Add missing tests for selector regexp matching (#16204)

This adds tests for the regex/glob style behavior that was added
in 045490de257e4348de169be5c85958d863567efc but not documented
until #10062.
gravitational/teleport,gravitational/teleport,gravitational/teleport,gravitational/teleport,gravitational/teleport,gravitational/teleport