[WIP] [Pull-based Ingestion] Introduce ingestion management APIs

[varunbharadwaj]

Description

This PR adds ingestion management APIs - mainly Pause, Resume and GetIngestionState APIs. This PR is a first version to introduce the APIs and subsequent PRs will build on this to support the following -

1. Pause/resume APIs will provide a 'wait' option which will wait till timeout for shards to update the state before returning a success response. In this PR, we return once acknowledged.
2. Resume API will support reset options.
3. GetIngestionState API will support pagination.

Related Issues

Part one of #17442

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[github-actions]

❌ Gradle check result for dcccf22: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?