Adding Watch API and initial implementation (#2281)

* Adding Watch API and initial implementation
- new API introduced in api.proto
- new proto-driver function to get a volume watcher that passes "modified/new/deleted" volume through a golang channel
- implement watcher go-routine that constantly wait for volume from the golang channel that passes from porx
- implement the pipeline that passes volume info from watcher go-routine to all streaming clients 

Tests: 
UT passed
Local smoke test with Porx

Signed-off-by: dahuang <[email protected]>

Makefile

@@ -429,6 +429,7 @@ mockgen:
  mockgen -destination=api/mock/mock_node.go -package=mock github.com/libopenstorage/openstorage/api OpenStorageNodeServer,OpenStorageNodeClient
  mockgen -destination=api/mock/mock_diags.go -package=mock github.com/libopenstorage/openstorage/api OpenStorageDiagsServer,OpenStorageDiagsClient
  mockgen -destination=api/mock/mock_volume.go -package=mock github.com/libopenstorage/openstorage/api OpenStorageVolumeServer,OpenStorageVolumeClient
+ mockgen -destination=api/mock/mock_watch.go -package=mock github.com/libopenstorage/openstorage/api OpenStorageWatchServer,OpenStorageWatchClient
  mockgen -destination=api/mock/mock_bucket.go -package=mock github.com/libopenstorage/openstorage/api OpenStorageBucketServer,OpenStorageBucketClient
  mockgen -destination=cluster/mock/cluster.mock.go -package=mock github.com/libopenstorage/openstorage/cluster Cluster
  mockgen -destination=api/mock/mock_fstrim.go -package=mock github.com/libopenstorage/openstorage/api OpenStorageFilesystemTrimServer,OpenStorageFilesystemTrimClient

SDK_CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Releases
 
+### v0.162.0 - (07/11/2023)
+
+* Add new Watch endpoint
+
 ### v0.161.0 - (06/12/2023)
 
 * Add auto-journal IO profile