* Editorconfig: Add space_before_self_closing setting
This was a difference between the way dotnet-format and Rider format code. See https://www.jetbrains.com/help/rider/EditorConfig_Index.html
* Editorconfig: Keep 4 spaces indentation for Swagger JSON files
They are all formatted that way, let's keep it like that.
* Apply dotnet-format, mostly white-space related changes
* 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
