Integrate drawing into feedback dialog

This adapts the feedback dialog by including the drawing option directly inside the feedback dialog to streamline the feedback process.

[Testlink](http://mf-geoadmin3.dev.bgdi.ch/gjn_feedback_variant2)

@oterral or @loicgasser Could you you code-review when you find the time?
Yes. In process of refactoring anyway because of a bug detected by @procrastinatio