Adding replication (CCR) plugin interface and classes to common-utils

[aggarwalShivani]

Description

Background:

• This change is required for a new feature being added in ism plugin - unfollow-action #726 - integrating ccr and ism plugins.
• For this feature, ism plugin needs to invoke stop-replication action from ccr. As both ccr and ism need to invoke some common code, the common code can be moved to common-utils, as done previously for other plugins too. For ex. notifications plugin
• As sharing of libraries also leads to a type-cast and class-loading issue - previously seen with notification plugin - the request object needs to be of a higher-level class from opensearch-core like ActionRequest and later be recreated into required type i.e. StopIndexReplicationRequest.

Proposed Solution:

1. Common-utils: Move common code of stop-replication from ccr project to common-utils.
2. CCR: Modify ccr plugin to consume classes from common-utils. Also, create a new TransportAction that transforms the request into required type and invokes TransportStopIndexReplicationAction.
3. ISM: Add new action in ism
   (FYI - This is an alternative approach for this feature. I had also raised a draft PR with a different approach, but we didnt go ahead with it as it required changes in opensearch-core as well.)

Change description:
Code for StopIndexReplicationRequest and StopIndexReplicationAction are moved to common-utils. Added UTs for both the new classes added.
This PR caters to point 1 of the proposed solution.

Issues Resolved

Related Issues
unfollow-action #726

Check List

• New functionality includes testing.
  • All tests pass
• [ ] New functionality has been documented.
  • [ ] New functionality has javadoc added
• Commits are signed per the DCO using --signoff

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[aggarwalShivani]

Hi,
For this change, some CI failures are due to AcknowledgedResponse moving to org.opensearch.action.support.clustermanager. Will repush once the integration issue with common-utils, ccr, ism on main branch is resolved
As discussed with @bowenlan-amzn, raised backport PR on 2.x branch (#789).

[aggarwalShivani]

Hi, For this change, some CI failures are due to AcknowledgedResponse moving to org.opensearch.action.support.clustermanager. Will repush once the integration issue with common-utils, ccr, ism on main branch is resolved As discussed with @bowenlan-amzn, raised backport PR on 2.x branch (#789).

Hi @bowenlan-amzn

The integration issue of common-utils and ccr is resolved with the merge of this change in ccr.
ISM continues to remain blocked though until this issue is resolved.

Meanwhile, as the changes for the stop-replication feature for both common-utlis and ccr are ready, requesting your review on this.
Backport PR is also ready for review #789

[bowenlan-amzn]

Suggested change

	open class ReplicationPluginInterface {
	object ReplicationPluginInterface {

[bowenlan-amzn]

Feels like the methods here should just be static methods.