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/backend_test.go

@@ -227,7 +227,7 @@ func TestResourceVersionAtomicInc(t *testing.T) {
 
 		v, err := resourceVersionAtomicInc(ctx, b.DB, dialect, resKey)
 		require.NoError(t, err)
-		require.Equal(t, int64(1), v)
+		require.Equal(t, int64(2), v)
 	})
 
 	t.Run("happy path - update existing row", func(t *testing.T) {
@@ -304,7 +304,7 @@ func TestBackend_create(t *testing.T) {
 
 		v, err := b.create(ctx, event)
 		require.NoError(t, err)
-		require.Equal(t, int64(1), v)
+		require.Equal(t, int64(2), v)
 	})
 
 	t.Run("error inserting into resource", func(t *testing.T) {
@@ -409,7 +409,7 @@ func TestBackend_update(t *testing.T) {
 
 		v, err := b.update(ctx, event)
 		require.NoError(t, err)
-		require.Equal(t, int64(1), v)
+		require.Equal(t, int64(2), v)
 	})
 
 	t.Run("error in first update to resource", func(t *testing.T) {
@@ -513,7 +513,7 @@ func TestBackend_delete(t *testing.T) {
 
 		v, err := b.delete(ctx, event)
 		require.NoError(t, err)
-		require.Equal(t, int64(1), v)
+		require.Equal(t, int64(2), v)
 	})
 
 	t.Run("error deleting resource", func(t *testing.T) {