Feat(eos_cli_config_gen): Allow PIM RP without groups

[gusmb]

Change Summary

Enhancement for PR #1484

Modify router_pim_sparse_mode data model to allow RP definitions without defining groups. This allows to
define an RP (inside or outside VRF) that applies to all multicast groups.

Related Issue(s)

Fixes #1521
Related to #1358

Component(s) name

arista.avd.eos_cli_config_gen

Proposed changes

Modified template to render the configuration based on the RP definition, leaving groups as optional:

{%             for rp_address in vrf.ipv4.rp_addresses | arista.avd.natural_sort('address') %}
{%                 if rp_address.groups is arista.avd.defined and rp_address.groups | length > 0 %}
{%                     for group in rp_address.groups | arista.avd.natural_sort %}
         rp address {{ rp_address.address }} {{ group }}
{%                     endfor %}
{%                 else %}
         rp address {{ rp_address.address }}
{%                 endif %}
{%             endfor %}

If groups is defined, the RP is defined for those groups, otherwise the RP is defined without groups, which applies by default to ALL multicast groups.

How to test

See molecule scenario

Checklist

User Checklist

• N/A

Repository Checklist

• My code has been rebased from devel before I start
• I have read the CONTRIBUTING document.
• My change requires a change to the documentation and documentation have been updated accordingly.
• I have updated molecule CI testing accordingly. (check the box if not applicable)

[ClausHolbechArista]

LGTM

[tgodaA]

LGTM