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.

script/gen_requirements_all.py

@@ -96,6 +96,7 @@ TEST_REQUIREMENTS = (
     'ring_doorbell',
     'rxv',
     'sleepyq',
+    'smhi-pkg',
     'somecomfort',
     'sqlalchemy',
     'statsd',