Introduce refactored aft summary model

[dplore]

Change Scope

• Refactor previously reverted Revert "Added new model for route summary" #992 route-summaries model to be OC Style guide compliant
• This change is backwards compatible (although the Revert "Added new model for route summary" #992 revert was a breaking change)

Platform Implementations

• JunOS show route summary
• Cisco XR OS show route summary
• Arista EOS show up route summary

Tree view

        |  +--ro oc-aftsummary:aft-summaries
        |     +--ro oc-aftsummary:ipv4-unicast
        |     |  +--ro oc-aftsummary:protocols
        |     |     +--ro oc-aftsummary:protocol* [origin-protocol]
        |     |        +--ro oc-aftsummary:origin-protocol    -> ../state/origin-protocol
        |     |        +--ro oc-aftsummary:state
        |     |           +--ro oc-aftsummary:origin-protocol?   identityref
        |     |           +--ro oc-aftsummary:counters
        |     |              +--ro oc-aftsummary:aft-entries?   oc-yang-types:counter64
        |     +--ro oc-aftsummary:ipv6-unicast
        |        +--ro oc-aftsummary:protocols
        |           +--ro oc-aftsummary:protocol* [origin-protocol]
        |              +--ro oc-aftsummary:origin-protocol    -> ../state/origin-protocol
        |              +--ro oc-aftsummary:state
        |                 +--ro oc-aftsummary:origin-protocol?   identityref
        |                 +--ro oc-aftsummary:counters
        |                    +--ro oc-aftsummary:aft-entries?   oc-yang-types:counter64

[OpenConfigBot]

No major YANG version changes in commit f489c24

[rolandphung]

Are we considering adding the old version back as deprecated to make this change truly backwards compatible?

[dplore]

The current plan of record regarding the old version (#783) is to not merge it back in. #992 is planned to stand as a breaking change because of the removal of the model and the next release of OC will be a major release (3.0).

We discovered the issue of a list with siblings when we attempted to use the model with ygnmi. It is not clear what may break if #783 is added back in, even if deprecated. Because openconfig tools are not tested or required to support siblings to a list the issue may not be merely cosmetic and I think it is advised to not to merge it back in.

We owe apologies to the community for not catching this issue during the review of #783. A check was added right after this issue was discovered to detect this issue in the future.

We will review the issues and this PR at the Nov 14, 2023 OC Operators meeting and at the forthcoming Dec 7, 2023 OC Community meeting.

[chrisy]

LGTM