New class for temperature/pressure fetching

[aSmig]

Existing code is dependent on OpenWeatherMap which requires an API key. I think we should continue making this option available for users who have an OWM key to get slightly fresher data but we should fall back on open-meteo which can be accessed without keys.

Example:
https://api.open-meteo.com/v1/forecast?latitude=45.5234&longitude=-122.6762&hourly=temperature_2m,pressure_msl

Laying this class out for ease of adding routines to fetch from other data source would be great.