v2: mark all Connector.<Call>/Connector.<Call>Typed/Connector.<Call>Async as deprecated

At now it is possible to make all request using Connector.Do() call. I'd like to mark all other request methods (Select, SelectTyped, SelectAsync, Delete, DeleteTyped...) as deprecated. The change will help us to remove them in the future:

1. The Connector interface will be easier to mock and use in tests.
2. There will be no duplication of functionality.
3. This will make our code smaller.