rac2: [dnm] implement handle raft event

[kvoli]

This commit implements HandleRaftEvent on the RangeController. When HandleRaftEvent is called by the Processor on the leader, the RangeController will perform local replica state management for the range and potentially return tokens if admitted has advanced. Additionally, any entries will subject to admission control will have corresponding tokens deducted and tracked.

Resolves: #129668 Release note: None