* Test typing for helpers.__init__ and temperature
* Add type hints to helpers.sun
* Add type hints to helpers.signal
* Add type hints to helpers.entity_values
* Add type hints to helpers.dispatcher
## Description:
More fixes flagged by pylint 2 that don't hurt to have before the actual pylint 2 upgrade (which I'll submit soon).
## Checklist:
- [ ] The code change is tested and works locally.
- [x] Local tests pass with `tox`. **Your PR cannot be merged unless tests pass**