* Rename tx downloader & verifier metrics
* Add version to mempool metrics
* Add new metrics
* Make sure mempool gauges are zeroed when instances are dropped
* Updated mempool grafana dashboard
* Removed transaction verification dashboard; moved to mempool
* Update mempool dashboard
* Add reason to error labels in mempool dashboard
* Rename some metrics per review
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>