API to read just the index of a symbol

[poodlewars]

Is your feature request related to a problem? Please describe.

We have the existing get_description APIs, or the _store.py get_columns and get_info APIs, but nothing similar for just for the index. This might be useful since although get_info includes the index name, it can be slow for very wide data.

Describe the solution you'd like A fast API to just get the index metadata. Possible approaches:

• New API method get_index_metadata or similar on Library and NativeVersionStore
• User supplied filtering as part of the get_description / get_info APIs to restrict the calculation and results to just what they are interested in

Discussion in Man Group: https://chat-man.slack.com/archives/CKD4V6N0H/p1702302484773229