Map-ol: concentrate UkisLayer/OlLayer conversion in one place

[MichaelLangbein]

Description

Currently, OlLayers are created from UkisLayers in map-ol.service.ts via the create_*_layer methods.
At the same time, updates to OlLayers from UkisLayers happen in map-ol.component.ts via the update*LayerParamsWith methods.

• This is inconsistent. It would be better for new developers to see all UkisLayer/OlLayer conversion in just one place.
• While changing (or even removing) the public methods update*LayerParamsWith would, strictly speaking, be an API change, I couldn't find any call to those methods from outside of map-ol.component at any point. In other words: this would, in my eyes, not constitute a significant change in API.

Relevant Package

This feature request is for @dlr-eoc/map-ol

[boeckMt]

Yes that's right!

In the beginning there was not much implemented, only the two functions addUpdateLayers and addUpdateBaseLayers
to set the order of layers on the map which are streamed from the LayerService.

We can try to implement this in the next major release. I think we have a couple of things that could be refactored which will bring also breaking changes such as: tha layer zIndex.

We can collect all of these things and then create v8.0.0 but before I like to close the other pull requests and create a version v7.3.0 because we already have created v7.3.0-next so v7.3.0 should not be missing :)