[5.0] Extracted Contracts

Extracted Database, View, Validation, Translation and Queue contracts.

Fixed some typos along the way

Only ones remaining are:
* `Illuminate\Routing\Annotations\EndpointInterface`
* `Illuminate\Routing\Matching\ValidatorInterface`
Please alias all contracts you import. In this case: `use Illuminate\Contracts\Database\Connection as ConnectionContract`. Also, you must sort the imports by length, shortest at the start, longest at the end.