Visual improvement of the `Register.qml` page
Visually the description text is moved closer to the ComboBox. Code-wise there are less items, but I added a hack to align the description of the ComboBox with the one of the TextSwitch.
Before:
After:
Spacing below the previous TextAreas was also weird, so I couldn't just place an item below the label (that's what prompted my to take a look at this in the first place).