[FEATURE] Create a Rest Endpoint for findLock method in LockService

[vibrantvarun]

Is your feature request related to a problem?
LockService has a method named findlock. It does not have a rest end point. Therefore, it is needed to create a rest end point in order to make debugging easier. This method is being heavily used in AcquireLock API and ReleaseLockApi, therefore in case of failure it will be super easy to debug.

What solution would you like?
Create a rest end point in SPI interface of Job Scheduler on path find/lock/{lockId} . Create a class named RestFindLockAction and define suitable extension points in JobScheduler Plugin like GetActions.

Do you have any additional context?

1. Understand the code-flow of AcquireLock and ReleaseLock API and try to understand how everything is working.
2. Create a new package with name rest under org.opensearch.jobscheduler.spi
3. Create a class named RestFindLockAction.
4. RestFindLockAction should extend abstract class BaseRestHandler
5. Override routes() and prepareRequest() method in RestFindLockAction class
6. Define two static strings in class
   public static final String FIND_LOCK_ACTION = "find_lock_action";
   public static final String LOCK_ID = "lock_id";
7. In routes method return a list of route with given Route below
   new Route(GET, String.format(Locale.ROOT, "%s/%s/{%s}", JobSchedulerPlugin.JS_BASE_URI, "_find_lock", LOCK_ID))
8. Override getName() method and return FIND_LOCK_ACTION
9. Create a public constructor in RestFindLockAction with LockService as argument and initialize the local variable

public RestFIndLockAction(LockService lockService){
this.lockService=lockService;
}

10. In prepareRequest method
    a) First fetch lockId from the RestRequest (refer ReleaseLockAction prepare request method)
    b) Initialize CompletableFuture object to make the search async
    c) Call lockService.findLock (refer ReleaseLockAction prepare request method)
    d) Return the channel response with the lockModel object

[nandiniverma08]

@vibrantvarun hey, Is this issue still open ? I wanted to work on this