WL#12080: Add support for binary log encryption key rotation and cleanup

Affects: Server-8.0   —   Status: Complete

High-Level Description / Executive Summary

EXECUTIVE SUMMARY
=================
This worklog implements the ability to rotate the binlog master key used
to encrypt file passwords of binary and relay log files.
The binlog master key should be rotated periodically and whenever you
suspect that the key may have been compromised.
Rotating the binlog master key not only changes the key used to encrypt
new file password, but also re-encrypts file passwords of previous existent
encrypted binary or relay log file with the new generated key. It also
cleanups the keyring, removing the binlog encryption keys generated by
the server that are not needed for server operation anymore.

User stories
============
- As a MySQL DBA/operator/instance owner, I want to rotate binlog encryption
  master key periodically without the need to restart the server in order to
  comply with security rules.
- As a MySQL DBA/operator/instance owner, I suspect that the some of existing
  binlog encryption master keys were exposed. I want to rotate the binlog
  master key so, starting this point, all new encrypted binary and relay log
  files shall use the new generated key to encrypt their file passwords, and
  file passwords of existent encrypted binary or relay log files are
  re-encrypted with the new generated key.