This change introduces a way of providing multiple listeners and pools
on the same Load Balancer, but with different L4 protocols.
In case there are more than one unique protocol defined in Octavia pools
or Octavia listeners the OVN driver now adds another Load_Balancer row
per protocol, but with the same name. The selection of which OVN
Load_Balancer should be used is done by a protocol key.
This change also adds possibility to expose two listeners on the same
port, but with different L4 protocol. The common use-case is providing
a DNS service that listens both on UDP and TCP sockets.
Partial-Bug: #1789157
Change-Id: I2ee13b75713e7538d1b4f70207a90a95315eb914
15260b7439