Proposal/Implementation for the status api

[neetikasinghal]

When trying to tier an index from hot to warm, the end-user should be able to track the status of the tiering. High-level status API model was already discussed as part of: #12501
The goal of this issue is as follows -

• Create a proposal for the status api highlighting the API model and design description
• Implement the status api for dedicated and non-dedicated setup

[e-emoto]

The API model for the design is in this issue here: #14640

[linuxpi]

[Storage Triage - attendees 1 2 3 4 5 6 7 8]

@neetikasinghal Thanks for creating this issue, please feel free to raise a PR!