Add metrics for out of view statement distribution errors (#4972)

* Add a simple metric for statements out-of-view

* Avoid repeated out-of-view peer reputation change messages

* Log reporting status

* Address review comments

* Use counter to store a number of unexpected messages from a peer

* Distinguish different unexpected statements in the metrics

* Fix labels cardinality

* Rename metric name to `statements_unexpected`

* Move metrics to a separate unit, avoid unnecessary enum

* Prefer specific methods in lieu of public constants