Support a COG-based image mosaic store

[JakobMiksch]

• adds function initCoverageStore
• adds function addGranuleByRemoteFile
• adapts function createImageMosaic
• adds function doesGranuleExist
• adds function enableTimeCoverageForCogLayer
  • somehow enableing time for a COG-based image mosaic does not work the same way as for a classic image mosaic
• switches GeoServer image for testing from meggsimum Docker image to official Docker image, because the COG extension does not seem to work properly with the meggsimum image. Adding three images in a row only applies the first and forgets the remaining ones. With the official GeoServer image the same process works:

  await grc.imagemosaics.addGranuleByRemoteFile(nsPrefix, coverageStore, 'http://nginx/cog/20220101T0200Z.tif');
  await grc.imagemosaics.addGranuleByRemoteFile(nsPrefix, coverageStore, 'http://nginx/cog/20220101T0300Z.tif');
  await grc.imagemosaics.addGranuleByRemoteFile(nsPrefix, coverageStore, 'http://nginx/cog/20220101T0400Z.tif');

• add sample COG data and mosaic store config
• move the Setting part of the tests to the very end, because it was messing up the other tests that were coming after it

TODO

• maybe find better name for enableTimeCoverageForCogLayer
• we have to wait until the offical GeoServer docker image has released version 2.22 see Upgrade GeoServer to 2.22.0 geoserver/docker#16 or we find a way to make the COG extension work with the meggsimum GeoServer image --> fixed meanwhile