Swedish weather institute weather component (#16717)

* SMHI Component

* Clean up typos

* Fixed default values first config to home location (tests will follow)

* Fixed tests and removed unused function

* Minor fixup after comments from @kane610

* add support for precipitation in forecast

* Removed old async_step_init not needed.

homeassistant/config_entries.py

@@ -146,6 +146,7 @@ FLOWS = [
     'mqtt',
     'nest',
     'openuv',
+    'smhi',
     'sonos',
     'tradfri',
     'zone',