Fix for issue #209 - Issue does not update when label is added

• Trigger update for labels if necessary after updating issues
• Trigger update for notes after issue is edited (Required if assignee is changed while editing the issue)
• Use notifyItemRangeChanged instead of notfiyDatasetChanged for updating notes

The primary source of bug was that the index is always 0 for notifyItemChanged however labels is in position 1. We would ideally want to determine if index 0 changed but considering how index 0 displays a lot of information a lot of comparison checks would be required. This shouldn't be issue right now as there are only two indices in the header but as more headers are added, a diff utility might be required that determines what actually changed in the issue object.

I wanted to follow up on this merge request. Would somebody be able to take a look at this?

Status changed to merged

Mentioned in commit 0b8b387b