* Add gRPC update debouncing mechanism
Implements backpressure handling for peer network map updates to
efficiently handle rapid changes. First update is sent immediately,
subsequent rapid updates are coalesced, ensuring only the latest
update is sent after a 1-second quiet period.
* Enhance unit test to verify peer count synchronization with debouncing and timeout handling
* Debounce based on type
* Refactor test to validate timer restart after pending update dispatch
* Simplify timer reset for Go 1.23+ automatic channel draining
Remove manual channel drain in resetTimer() since Go 1.23+ automatically
drains the timer channel when Stop() returns false, making the
select-case pattern unnecessary.
