[Map] [Toc] Enable Zoom limitations for Layer types

[ChristophMaskos]

Issue description

Please adopt the following properties from the Openlayer API for WMS layers:

minResolution:  (number| undefined) The minimum resolution (inclusive) at which this layer will be visible.
maxResolution:  (number| undefined) The maximum resolution (exclusive) below which this layer will be visible.
minZoom:  (number| undefined) The minimum view zoom level (exclusive) above which this layer will be visible.
maxZoom:  (number| undefined) The maximum view zoom level (inclusive) at which this layer will be visible.

Link

Layers that are not within the permitted zoom range should appear as disable in the Toc. Similar to a failed health check.

Validations

• Read and follow our code of conduct
• Read the contributing guidelines
• Check that there isn't already a similar issue

[mbeckem]

Good suggestion. For the time being, you can work around this by using the olLayer directly, for example

const layer: WMSLayer = ...;
layer.olLayer.setMaxZoom(...);

However I do agree that this is awkward. And it isn't displayed in the TOC.

Notes

• Should be implemented for all "real" layers that are backed by an olLayer, not just WMS.
• Consider adding the extent and opacity properties as well while we're at it.
• Needs constructor param, getter and setter. The ol properties are observable, so the getters should be reactive.
• For displaying in the toc: check whether open layers provides the information itself (layer "really" visible in zoom level). Otherwise, compute it based on zoom / resolution.