Add forbidden capabilities

[WebSpider]

Forbidden capabilities are capabilities that cannot be present for a sensor to be added.
They are effectively the reverse of required capabilities, that must be present for a sensor to be added.

The logic added in this PR is follows:

• A sensor will be added when the vehicle has none of the capabilities in forbidden capabilities and all of the capabilities in required capabilities

Example here is the battery-care switch for a Superb iV:
The Superb iV does not have the function, but it does support the CHARGING capability.

When you add the CHARGING_MQB capability to the forbidden capabilities, the battery-care switch will now never be added for the Superb iV:

[WebSpider]

This is related to #166

[dvx76]

While it looks like this will be usable for the specific case of #166 , I do wonder if this isn't oversimplifying things. Wouldn't it be conceivable that some models with the CHARGING_MQB capability support the charging limit, while other don't?

Wouldn't it be better to use the errors in the response from the charging (and I guess others) endpoint, which explicitly conveys the information we need?

E.g. from the suber_iv fixture:

    errors:
    - description: Care mode is not available.
      type: CARE_MODE_IS_NOT_AVAILABLE
    - description: Auto unlock is not available.
      type: AUTO_UNLOCK_IS_NOT_AVAILABLE
    - description: Charge limit is not available.
      type: CHARGE_LIMIT_IS_NOT_AVAILABLE

[WebSpider]

I guess without the knowledge of the actual API structure, we can only guess at what would be conceivable and what not. We have to make an educated guess at some point, this was mine ;-)

I would like think Skoda implemented the CAPABILITIES for a reason, but yes, you are right, it is conceivable a car with the CHARGING_MQB capability has other CHARGING related capabilities. When I look at what Wikipedia says on the MQB platform, it does seem unlikely, which is why I chose this path:

https://en.wikipedia.org/wiki/Volkswagen_Group_MQB_platform#MQB_Evo_(2019)