webrtcbin: use regular ice nomination by default

webrtcbin: use regular ice nomination by default

1. We don't currently deal with an a=ice-options in the SDP which means
   we currently violate https://tools.ietf.org/html/rfc5245#section-8.1.1
   which states: "If its peer is using ICE options (present in
   an ice-options attribute from the peer) that the agent does not
   understand, the agent MUST use a regular nomination algorithm."
2. The recommendation is default to regular nomination in both RFC5245
   and RFC8445.  libnice change for this is
   https://gitlab.freedesktop.org/libnice/libnice/-/merge_requests/125
   which requires an API break in libnice.

Change-Id: I672c2d92b2ac258b563ed7a77a263502d1656bd2
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2031>