Support REALTIME tables in reload status (segment metadata API)

[npawar]

This PR #5718 introduced the metadata API on the controller, which provides indexing info for each segment from the segments on the server. However, it is not handling REALTIME tables as of now.
Add support for realtime tables.
Once added, also ensure the Pinot Cluster Manager i.e. Pinot UI is able to show it for realtime tables (Reload Status button)

[ramabme]

Committed below change to fix above issue. Fixed the UI button and REST API.
#7169

[npawar]

Thanks @ramabme ! Closing this.