* Create historian metrics and dependency inject
* Record counter for total number of state transitions logged
* Track write failures
* Track current number of active write goroutines
* Record histogram of how long it takes to write history data
* Don't copy the registerer
* Adjust naming of write failures metric
* Introduce WritesTotal to complement WritesFailedTotal
* Measure TransitionsFailedTotal to complement TransitionsTotal
* Rename all to state_history
* Remove redundant Total suffix
* Increment totals all the time, not just on success
* Drop ActiveWriteGoroutines
* Drop PersistDuration in favor of WriteDuration
* Drop unused gauge
* Make writes and writesFailed per org
* Add metric indicating backend and a spot for future metadata
* Drop _batch_ from names and update help
* Add metric for bytes written
* Better pairing of total + failure metric updates
* Few tweaks to wording and naming
* Record info metric during composition
* Create fakeRequester and simple happy path test using it
* Blocking test for the full historian and test for happy path metrics
* Add tests for failure case metrics
* Smoke test for full annotation persistence
* Create test for metrics on annotation persistence, both happy and failing paths
* Address linter complaints
* More linter complaints
* Remove unnecessary whitespace
* Consistency improvements to help texts
* Update tests to match new descs
* Loki backend and client depend on a requester
* Instrument all requests to loki using weaveworks TimedClient
* Construct collector in metrics package
