Elasticsearch7 - Collections not appearing in search results in MySQL8

[Dianne Tennent]

A fix for this issue was included in the main Elasticsearch 7 patch: https://reviews.mahara.org/c/mahara/+/12105 (but may only have been tested with postgres)

MySQL8+Firefox on main

To replicate:
1. Add a person to the site
2. Enable Elasticsearch 7, select all artefact types and index the site
3. Masquerade as the person you added
4. Create a page and add it to a collection
5. Run the cron to reindex the site
6. Type a keyword of the Collection title in the search field, click the search button and select the 'Portfolios' tab

Expected:
 - Title of Collection appears or pages that are in Collections are indicated as such

Actual:
 - Only pages appear and you cannot search by Collection title

[Robert Lyon (robertl-9)]

When I did a test using MySQL 8 and docker version of Elasticsearch 7 I was able to add a collection and search for the collection by title and see the collection listed under the 'Portfolio' tab as expected and it looks similar to what I see for a collection under the Elasticsearch 5 search