Convert BackupReceiver to component

The BackupReceiver instance is created by BackupReceiverRepository and it needs access to the Cache instance for its dependencies.

However, with the latest changes in Cross-Site Replication, it needs to be accessed by commands and the only way to do it is by doing:

BackupReceiver backupReceiver = registry.getGlobalComponentRegistry()
            .getComponent(BackupReceiverRepository.class)
            .getBackupReceiver(cache);

Bottom line: tt should be converted to a component.

Another alternative would be to merge it with PerCacheInboundInvocationHandler... but it doesn't sound too good since it will increase the complexity and size of PerCacheInboundInvocationHandler