[new compiler] Implement proper type resolution

Collect all references to unknown types after parsing, re-use the existing code
in QQmlTypeLoader to resolve them and finally use the resolved references map
in the QQmlObjectCreator instead of the type name cache directly.

Change-Id: I8b83af4f8852e79c33985457081c024358bb9622
Reviewed-by: Lars Knoll <lars.knoll@digia.com>