Quick work around for creating MySQL 8 users/roles/databases

[kevindew]

Trello: https://trello.com/c/HjK4AbUS/49-configure-puppet-for-new-db-admin-mysql-instances

The mysql puppet version we use does not have the correct syntax for
creating users for MySQL 8 1 (well not in a version that is compatible with
Puppet 3.x, which is understandable)

This runs the commands to do these tasks without utilising the puppet
module and instead running the queries directly.

This worked (after a bit of trial and error) on a Whitehall DB Admin
box:

kevindew@ec2-integration-blue-whitehall_db_admin-ip-10-1-5-75:~$ govuk_puppet --test
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Loading facts
Info: Caching catalog for i-0a640e087db1a2f7a
Info: Applying configuration version 'c61812e33b1338ea166bac466374c58daae2a454'
Notice: /Stage[main]/Govuk::Apps::Whitehall::Db/Exec[create_whitehall_user]/returns: executed successfully
Notice: /Stage[main]/Govuk::Apps::Whitehall::Db/Exec[create_whitehall_fe_user]/returns: executed successfully
Notice: /Stage[main]/Govuk::Apps::Whitehall::Db/Exec[create_whitehall_production_db]/returns: executed successfully
Notice: /Stage[main]/Govuk::Apps::Whitehall::Db/Exec[grant_whitehall_fe_user]/returns: executed successfully
Notice: /Stage[main]/Govuk::Apps::Whitehall::Db/Exec[grant_whitehall_user]/returns: executed successfully
Notice: Finished catalog run in 7.01 seconds

There's a few things about this though which don't make it suitable as a
merge contender currently:

1. This uses syntax that isn't understood by MySQL 5.6 - so it will
   error when ran on an existing box, it'll need some way to alternate
   between approaches
2. I'm not sure I've got puppet dependencies set-up particularly
   elegantly, I couldn't remember how things worked and guessed a bit
   with require - I think some commands should depend on the MySQL
   package but that didn't work for me. It might be better to just have
   one script of MySQL that's executed rather than a bunch of commands
3. I'm not sure how to get it to not execute every puppet run, like the
   MySQL module currently does - I don't think it'll be

This does rely on the mysql_password function that I believe the puppet
module exposes.

The alternative to do something like this is creating the database and
users on the machines manually - this isn't the most arduous process as
they are created very infrequently

[ChrisBAshton]

Closing in favour of #11372. (Thanks for investigating though, Kevin!)