Use a dedicated `CNode::m_avalanche_message_fault_score` member variable to track repeated avaresponse message faults, and call `Misbehaving(*peer, 100)` when that score reaches a threshold instead of incrementing the misbehavior score by 2 directly.
In a case in which the only source of misbehavior is the avaresponse faults, the behavior is unchanged. If the misbehavior score is incremented for other reasons, now we are a bit more tolerant of network faults.
This prepares the codebase for a following diff ([[https://github.com/bitcoin/bitcoin/pull/29575 | core#29575]]) in which we will stop tracking the misbehavior score, and calling `Misbehaving` will immediately trigger discouragement.
Depends on D18018