API Skills/Consolidating Duplicated Skills

[NeonDaniel]

There are a number of duplicated skills (i.e. mycroft, ovos, neon, and probably others have different "weather" skills). Lets brainstorm how we might avoid so much duplicated code that is co-maintained for the same purposes.

One idea is to leverage the skill api (https://mycroft-ai.gitbook.io/docs/skill-development/skill-structure/api) and maintain a single skill that handles the logic, with derivatives that only deal with intent handling. A side-affect of this is that it encourages more methods being exposed to the messagebus.

Another option is to encourage derivative skills to import and extend some base skill; this would potentially add work for skill maintainers, as it makes a skill more like an API when derivatives expect to extend a particular method. Note that there is no reason you can't do this now; pip-installable skills (#61) would make this almost trivial.