Add config_flow and stream selection to foscam (#41429)

* Add config_flow and stream selection to foscam

* Simplify config_flow steps

* Make debug log entry more useful

* Deprecate config and platform schemas

* Simplify config loading

* Add config flow testing

* Remove unneeded CONFIG_SCHEMA deprecation

* Improve test coverage

* Unload service by tracking loaded entries

* Address comment

Co-authored-by: Paulus Schoutsen <paulus@home-assistant.io>