sync back map changes to config object

[silvester-pari]

update the config property same as layers property (layers, view, controls)

[santilland]

As we usually should be using an eox-map configuration i don't see this as a too important functionality. The possibility to be able to export the current OL state as config #909 i think would be enough.

[santilland]

So i think i misunderstood the importance of this, as it is possible to make many changes with the layer controls, i very much think we need to make sure that map changes affect the config object, at the very least that changes done by the layer controls are reflected.
What do you think @silvester-pari and @RobertOrthofer ?

[silvester-pari]

This issue is specifically for the config property of the eox-map, which is a shorthand to define layers, view, and controls all at once. If you find something in e.g. the layers property that is not properly synced, could you open a dedicated issue for that?

[santilland]

So the layers property should be synced? As far as i could observe if i modify for example the visibility with the layer control, this is not reflected in the layers property.
Would that be an issue for the layers control or still really an issue of the eox-map?

[RobertOrthofer]

opacity, visibility, zIndex and custom properties should be synced back to the _jsonDefintion of each layer, appearently this is not synced back to the actual layers-property. I'm not sure if this is a regression or if this 2-way-reactivity was never fully implemented (#476)

If I remember correctly though we paused the 2-way-reactivity-approach for a clean 1-way-reactivity and the possibility to extract the current state of the element on demand