The first try wasn't exhaustive. I was planning to use
1f933263e7/store/sqlstore/post_store.go (L1738-L1748) for this
but it also contained `@` which we don't want.
In the end, I just used a separate slice for all
the characters to be escaped.
https://mattermost.atlassian.net/browse/MM-46871
```release-note
NONE
```
Co-authored-by: Mattermod <mattermod@users.noreply.github.com>