Aemet-opendata

- const: add more constants

- helpers: add new function to retrieve day values
- Add new constants

- Fix and add new constants

- helpers: forecast: allow changing search key

- interface: remove incorrect function
- Add and refactor constants

- interface: add support for retreiving latest station data
- const: code cleaning
- helpers: add functions to retrieve forecast hour values
- Manifest: remove duplicated file