All elements now use the elementValueChanged event. Also
formValueChanged is changed.

Use flex to position image and text below one another. Don't use any 
image scaling setting. Now the images grow but don't shrink.

There were some things missing when renaming questions/answers to 
rows/columns. Now everything is properly named.

Since this is built using a grid it does not need dimensions. In fact it 
having dimensions interferes with styling.

* Add IntersectionService
* Add CompoundElementComponent as parent for LikertComponent
* Inject ElementRef to common ElementComponent
* Rename players' ElementComponent to ElementContainerComponent

Other elements do implement the interface but do nothing with the 
property. This make all the interface handling a lot easier at the cost 
of having useless variables in some contexts.

* Remove FormService Injection
* Move FormService and form types to player
* Move interface ValueChangeElement to uI-element.ts
* Use interface InputElementValue instead of
string | number | boolean | null

* Add `InputElementValue` as type when needed

Colors and font stuff.