Support Layers of types COG and XYZ

Description

Add support for common layer types COG and XYZ in GeoGirafe.

Job done

Add 2 new layer types : LayerCog and LayerXYZ, and make them work with GeoGirafe. As those layer types are currently not supported by the backend, they can only be used if defining the themes.json manually.
This only works with WebGL Tiles.
Because we in Basel so not have any public COG yet, I had to download an exemple from here: https://www.swisstopo.admin.ch/en/national-map-swiss-map-raster-10 and add it locally on the dev server (simply copy it to /public)

Can be tested with the following configuration (manually added somewhere in themes.json):

          "children": [
            {
              "id": 99998,
              "name": "ArcGIS Imagery XYZ",
              "type": "XYZ",
              "url": "https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{z}/{y}/{x}"
            },
            {
              "id": 99997,
              "name": "Swisstopo Map Raster COG",
              "type": "COG",
              "url": "/swiss-map-raster10_2024_1047-4_krel_0.5_2056.tif"
            }
          ],

Definition of Done

For the Developer:

• Code compiles and conforms to defined coding standards (eslint, tsc, prettier).
• If necessary (at the developer's discretion), unit tests have been added for critical parts.
• All unittests run without error.
• Sonar-Scan returns no new issues or security hotspots.
• Documentation has been updated where necessary (see documentation repository).
• Merge-Request contains a few explanations of what was done.
• A Reviewer has been assigned to the Merge-Request.

For the Reviewer:

• New code was reviewed.
• If comments could be added on unclear code, the developer has been informed.
• If unitests could be added in certain places, the developer has been informed.
• Merge-Request was merged on main branch.
• All pipelines work.
• The changes were tested on demo environment.
• Application performance has not been degraded by the modifications.