Update channel member notify props to use native JSON (#18114)

* Update channel member notify props to use native JSON

Created a new store method that patches the notify props field.

https://community-daily.mattermost.com/plugins/focalboard/workspace/zyoahc9uapdn3xdptac6jb69ic?id=285b80a3-257d-41f6-8cf4-ed80ca9d92e5&v=495cdb4d-c13a-4992-8eb9-80cfee2819a4&c=91d08676-4a0e-4f02-8dce-d24d4fc56449

```release-note
NONE
```

* cleanup

```release-note
NONE
```

* forgot to commit

```release-note
NONE
```

* Fix edge case

```release-note
NONE
```

* address review comments

```release-note
NONE
```

* fix incorrect order

```release-note
NONE
```

* Address review comments

```release-note
NONE
```

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

store/retrylayer/retrylayer.go

@@ -2348,6 +2348,26 @@ func (s *RetryLayerChannelStore) UpdateMember(member *model.ChannelMember) (*mod
 
 }
 
+func (s *RetryLayerChannelStore) UpdateMemberNotifyProps(channelID string, userID string, props map[string]string) (*model.ChannelMember, error) {
+
+	tries := 0
+	for {
+		result, err := s.ChannelStore.UpdateMemberNotifyProps(channelID, userID, props)
+		if err == nil {
+			return result, nil
+		}
+		if !isRepeatableError(err) {
+			return result, err
+		}
+		tries++
+		if tries >= 3 {
+			err = errors.Wrap(err, "giving up after 3 consecutive repeatable transaction failures")
+			return result, err
+		}
+	}
+
+}
+
 func (s *RetryLayerChannelStore) UpdateMembersRole(channelID string, userIDs []string) error {
 
 	tries := 0