Agent based IPV6 only install fails when the RendezvousIP is not canonical

When doing an IPV6 only agent based installer on bare metal this fails if the RendezvousIP value is not canonical. 

OCP 4.12

Every time.

1. Configure the agent through agen-config.yaml for an IPV6 only install.
2. Set to something that is correct, but not canonical: 
   for example: rendezvousIP: 2a00:8a00:4000:020c:0000:0000:0018:143c 
3. Generate discovery iso and boot nodes. 

Installation fails because the set-node-zero.sh script fails to discover that it is running on node zero.

Installation completes. 

The code that detects wether a host is node-zero uses this:

is_rendezvous_host=$(ip -j address | jq "[.[].addr_info] | flatten | map(.local==\"$NODE_ZERO_IP\") | any")

This fails in unexpected ways with IPV6 that are not canonical, as the output of ip address is always canonical, but in this case the value for $NODE_ZERO_IP wasn't. 

We did test this on the node itself: 

[root@slabnode2290 bin]# ip -j address | jq '[.[].addr_info] | flatten | map(.local=="2a00:8a00:4000:020c:0000:0000:0018:143c") | any' 
false

[root@slabnode2290 bin]# ip -j address | jq '[.[].addr_info] | flatten | map(.local=="2a00:8a00:4000:20c::18:143c") | any'
true

A solution may be to use a tool like ipcalc, once available, to do this test and make it less strict. In the mean time a note in the docs would be a good idea.