Fixes #15861 - increase size of audited_changes column

In mysql text type is limited to 64K, while in psql
there's no limit. Changeing type to MEDIUMTEXT,
which limited to 16MB, should solve this issue in mysql

Fixes #19700 - update rubocop rules

The following changes have been made:

- Performance/RedundantMerge:
changes lines such as:
```not_found_message.merge! :message => options```
to:
```not_found_message[:message] = options```

- converts str.match() to str =~ ()...

Fixes #19612 - CVE-2017-7505 don't expose admin to taxed users

Fixes #19632 - changed shim and grub1 PXE names

Fixes #19459 - improve vm boot failure feedback

To be able to override the wait for vm ready we need to move
it to compute resource definition. Also improve Openstack one

refs #19534 - check EncryptValue class variables are defined

bed4594 added class variables to record logging state, but failed to
check it was defined before accessing them, causing exceptions when
decryption failed. Tests added for this new behaviour.

Fixes #19534 - removed excessive encryptor logging

Fixes #19534 - improved orchestration task logging

Fixes #19506 - reset cache after CR update

Fixes #19173 - build notification succeeds with expired token.