* Add in-memory cache for bandwidth and space usage monitoring
* moved some structs around and added error handling for get piece size query
* added to existing bandwidth test. fixed typo
* added test, updates from PR review, added monkit for new methods
* PR review updates. renamed space used methods
* changed bw cache so that only Add updates the cache and it only overwrites when the date moves forward
* moved bandwidth usage to bw and space usage to pieceinfodb
* fixed interface comment
* removed pointer from sync.Once
What: add monkit.Task to a bunch of functions that are missing it
Why: this will significantly help our instrumentation, data collection, and tracing about what's going on in the network
* first round cleanup based on go-critic
* more issues resolved for ifelsechain and unlambda checks
* updated from master and gocritic found a new ifElseChain issue
* disable appendAssign. i reports false positives
* re-enabled go-critic appendAssign and disabled lint check at code line level
* fixed go-critic lint error
* fixed // nolint add gocritic specifically
