Make VIP_Request_Block::block_and_log() public to stop the need for duplicating functionality

Previously if we wanted to block on something more custom that what was available in VIP_Request_Block, we’d need to copy the functionality into vip-config.php. By making VIP_Request_Block::block_and_log() public we no longer need to do this duplication.

https://github.com/Automattic/vip-go-mu-plugins/pull/1993