Add support for the "routing igmp-proxy" path

[hansmi]

SUMMARY

Upstream documentation: https://help.mikrotik.com/docs/display/ROS/IGMP+Proxy

ISSUE TYPE

• Feature Pull Request

[github-actions[bot]]

Docs Build 📝

Thank you for contribution!✨

This PR has been merged and the docs are now incorporated into main: https://ansible-collections.github.io/community.routeros/branch/main

[felixfontein]

@hansmi thanks!