Add config flow to transmission (#26434)

* Add config flow to transmission

* Reworked code to add all sensors and switches

* applied fixes

* final touches

* Add tests

* fixed tests

* fix get_api errors and entities availabilty update

* update config_flows.py

* fix pylint error

* update .coveragerc

* add codeowner

* add test_options

* fixed test_options

script/gen_requirements_all.py

@@ -173,6 +173,7 @@ TEST_REQUIREMENTS = (
     "srpenergy",
     "statsd",
     "toonapilib",
+    "transmissionrpc",
     "twentemilieu",
     "uvcclient",
     "vsure",