Unistore : Ensure Watch works in HA mode. (#93428)

* Replace Watch with WatchNext

* remove watchset

* fix previous page and closing the channel

* Remove the broadcaster cache to prevent dupplicated events

* add watch bookmark

* add watch bookmark

* cleanup comments

* disable the tests for bookmarks for now

* Ensure we send previosu events

* lint

* re-introduce the cache

* load from cache

* disabling legacy test

* disabling legacy test

* Update pkg/storage/unified/resource/server.go

Co-authored-by: Diego Augusto Molina <diegoaugustomolina@gmail.com>

* Could not read previous events

* add proper migration

* Add previous_resource_version to both history and resource

* First event should have an RV of 2 and not 1

* Test both storage backends

* fix the inital RV for the sql backend

* ensure graceful stop of the stream decoder

* gocyclo

---------

Co-authored-by: Diego Augusto Molina <diegoaugustomolina@gmail.com>

pkg/storage/unified/sql/queries.go

@@ -70,6 +70,7 @@ func (r sqlResourceRequest) Validate() error {
 type historyPollResponse struct {
 	Key             resource.ResourceKey
 	ResourceVersion int64
+	PreviousRV      int64
 	Value           []byte
 	Action          int
 }
@@ -101,6 +102,7 @@ func (r *sqlResourceHistoryPollRequest) Results() (*historyPollResponse, error)
 			Name:      r.Response.Key.Name,
 		},
 		ResourceVersion: r.Response.ResourceVersion,
+		PreviousRV:      r.Response.PreviousRV,
 		Value:           r.Response.Value,
 		Action:          r.Response.Action,
 	}, nil