Denormalise notes permission data and update notes in ES when project permissions change

Denormalise the notes permission data per &2054 .

Denormalise the project issues visibility level and project visibility level onto the notes document type. This requires a migration to update all the existing notes with this field. It also requires triggering a notes update in Elasticsearch for all associated notes whenever the project permissions change.

There are notes on 4 types of objects indexed in Elasticsearch: Commit, Merge Request, Issue, and Snippet. Each of the related project permissions will need to be denormalised.