* simplify settings changed listening
Might as well use the Event aggregator to listen in on changes instead of the current complicated magic in the settings repo. This also reduces db calls( it sends the new settings through the event instead of fetching them again)
* add settings extension
* switch to old style but using event aggregator
* BitcoinSpecificBtcPayNetwork - abstract BTCPayNetwork
* some type fixes
* fix tests
* simplify fetching handler in invoice controller
* rename network base and bitcoin classes
* abstract serializer to network level
* fix serializer when network not provided
* fix serializer when network not provided
* fix serializer when network not provided
* try fixes for isolating pull request
