RSDK-13879 - revert no-cert, fix mdns connection

[stuqdog]

• Reverts no-cert check now that our certs aren't leaf-only.
• Creates more nuanced tiering of preference for URIs (prefer non-loopback local, then prefer loopback local, then prefer whatever)
• Don't try to dial via webRTC when using mDNS, which will fail and lead to a fallback which doesn't work in the offline case.

Tested locally in offline and online cases, successfully connected via mDNS.