wireshark: disable gtk+ frontend unless with-x is passed

Fixes #20528.
Add minimum OS X version requirement

Closes #19998.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
Use minimum OS X requirement
wireshark: use gnutls 3

Closes #20547.
Redact gnutls2

Wireshark accepts gnutls3, so nothing else in core needs version 2.
Fix Xcode builds on 10.9.

CLT-only builds are still broken and need to be fixed at some point.

Closes #20524.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>