#24082 Added support for updating frameworks.

This change allows for an app/engine/framework manifest definition on
the following form:

```
frameworks:
    - {"name": "tk-framework-foobar", "version": "v0.x.x"}
```

This is a backwards compatible change which means that the app with the
above manifest would automatically receive any v0.x.x updates as they
happen. These updates are retrieved using the standard tank updates
command which has been extended to support updating frameworks.

The change covers both git and app_store descriptors types.