Convert database tables to utf8mb4
This is a follow up issue for #167 (closed).
The convert_to_utf8 task however increases the max size of the database fields though due to the way ALTER TABLE CONVERT TO CHAR SET utf8mb4 ...
works:
https://dev.mysql.com/doc/refman/5.5/en/alter-table.html#alter-table-character-set
We probably want something closer to the second script here: https://railsmachine.com/articles/2017/05/19/converting-a-rails-database-to-utf8mb4.html
Not sure if we need the ptosc magic though.