Description:
- Added following component services
  1. keyring_load
  2. keyring_reader_with_status
  3. keyring_writer
  4. keyring_generator
  5. keyring_aes
  6. keyring_keys_metadata_iterator
  7. keyring_component_status
  8. keyring_component_metadata_query

- Added two keyring components that
  implements above mentioned services
  1. File based keyring component
  2. Encrypted file based keyring component

- Added lock-aware implementation of all
  keyring services in server_component.
  This will be the default implementation.

- Added bridge implementation of a subset
  of services mentioned above that calls
  corresponding services implemented by
  a keyring plugin.

- Updated all callers of keyring plugin
  services to use new component service
  APIs
  1. InnoDB Encryption
  2. Binary Log Encryption
  3. Audit Log Encryption

- Added new keyring migration binary -
  mysql_migrate_keyring to migrate data
  from one keyring component to another
  one.

- Updated MySQL server's keyring migration module
  to support keyring component as destination.

- Added performance_schema.keyring_component_status
  table

- Added support for manifest file in server.
  Keyring component must always be loaded
  through manifest file because keyring
  requires initialization step and must be
  available very early during server start-up

- Added required MTR tests and unit tests
  to test keyring component functionality.

RB: 242944