To do so we update CValidationInterface::BlockDisconnect to take a
CBlockIndex pointing to the block being disconnected.
This new parameter will be use in the following commit to establish
wallet height.
https://github.com/bitcoin/bitcoin/pull/15931/commits/10b4729e33f76092bd8cfa06d1a5e0a066436f76
Partial backport of Core PR15931