Description:
- Added a new program option and new system variables
  to specify TLS material/configuration for admin
  interface
- Added new plugin variable for group replication
  to configure source for the TLS material
- Updated ALTER INSTANCE RELOAD TLS to add support
  for changing TLS configuration for admin interface
  at runtime
- Introduced new instrumentation type in performance
  schema - TLS channel instrumentation
  - Added support for plugins to register for new
    instrumentation
  - Added new component services for instrumentation
  - Added new table - performance_schema.tls_channel_status
    to display TLS information for registered channels
- Added required tests for new functionality

RB: 24027