lib: Print multicast-source-interface rmap match

[csiltala]

Fix missing cli_show portion for rmap-match-condition/frr-pim-route-map:multicast-source-interface

[greptile-apps]

Greptile Summary

This PR restores CLI rendering for the PIM multicast source interface route-map match. The main changes are:

• Added a matcher for frr-pim-route-map:multicast-source-interface.
• Added show running-config output for match multicast-source-interface <interface>.
• Reused the same YANG path pattern as the existing multicast interface match.

Confidence Score: 5/5

This looks safe to merge.

• No blocking issues found in the changed code.

Important Files Changed

Filename	Overview
lib/routemap.h	Adds the route-map condition matcher for the PIM multicast source interface match type.
lib/routemap_cli.c	Prints the multicast source interface match when rendering route-map configuration.

_{Reviews (2): Last reviewed commit: "lib: Print multicast-source-interface rm..." | Re-trigger Greptile}

[Jafaral]

Thanks! I tested the fix locally and now I can see the route-map in the configs.

[Jafaral]

@Mergifyio backport stable/10.7

[mergify]

backport stable/10.7

✅ Backports have been created

Details

• #22618 lib: Print multicast-source-interface rmap match (backport #22612) has been created for branch stable/10.7