[Bug] Node doesn't disconnect from forked peers

[vicsn]

🐛 Bug Report

A client node could not sync and experienced the following errors. I assume because they receive blocks from an invalid forked other node. On detection of such a failure, we should disconnect from the peer which experienced a failure.

Note that there may be some dead code related to banning logic in snarkOS. We had this feature until recently but it was underspecified and undertested.

[kaimast]

This should be fixed by #4094, but I need to test and verify it.