Improve default ui schema generation

**Is your feature request related to a problem? Please describe.**
The default ui schema generation works fine for most cases but it's missing some edge cases. For example it does not produce a `Control` for a property which has `enum` defined but no `type`.

**Describe the solution you'd like**
Check and test all schema edge cases. Especially check for shortcuts where no `type` is required.

**Describe alternatives you've considered**
In addition we could allow the user to customize the ui schema generation.

**Describe for which setup you like to have the improvement**
Framework: [core]