also adding it to all properties used by the r/o widget
This needs to be done by a lot more r/o widgets, if they assign their default values in the constructor!
- Missing border in Et2DateDuration without unit selector
- Box alignment was not applied to widget inputs (Et2DateDuration) when the widget inputs did not fill all available space
@Nathan: Not sure if this is the right fix, but I can't see where we use Lit's FormatMixing, which defines serializedValue (and therefore select-box always returns the old modalValue)
Paying more attention to the WebComponent life cycle here, rather than what our widgets do - connectedCallback(), requestUpdate(), updated() are more important than loadFromXML(), etc. which are only used when loading from the .xet the first time.
