* Make stop functions wait for completion before return.
* Implement graceful shutdown.
* Shutdown rpc and metric servers if enabled.
* Move metrics and rpc servers out of PortalNode.
* Add nph check to fluffy CI lint
* Add a section on nph usage in the fluffy.guide
* Update copyright years for altered files
* Avoid chained methods formatting style in db code
* Update nph in CI to v0.5
* Remove leftover commented import
* Move comment to avoid nph turning complex list into simple list (nph bug)
* Update nph in CI to v0.5.1
* Formatting fluffy with nph v0.5.1