Support Geoserver WCS DimensionDomain

[eblondel]

Relates to #114 (vignette) and Emodnet Biology examples that now fail, with the introduction of a new dimension (SEASON) in some WCS coverages. This raises various enhancement issues:

• Need to support a proper class to handle DimensionDomain blocks
• Need to be able to parse Geoserver coverage descriptions with its specific classes (including the new one for dimensions). This is a challenge, as a WCSCoverageDescription is a generic class extending GMLCOVAbstractCoverage, and not a specific Geoserver WCS coverage description with its specific elements/classes (WCSGSTimeDomain,WCSGSElevationDomain,WCSGSDimensionDomain)
• Need to integrate the new class for DimensionDomain and refactor the logic of others in getDimensions() method
• Integrate the business logic to share these additional dimensions into the GetCoverage request

cc @salvafern

[eblondel]

@salvafern I'm evaluating how much work is required, in case VLIZ is interested to get this feature, as it may retrieving block N-dimension raster data cubes like the one presented in the WCS vignette.

FYI, This was not part of the WCS client developments done in the past because it deals with specific implementation of Geoserver. it's apparently an extension of Geoserver over the WCS standard. Indeed these classes deal with a namespace that is specific to Geoserver: http://www.geoserver.org/wcsgs/2.0 (and underlying schema: ../geoserver/schemas/wcs/2.0/wcsgs.xsd )

[eblondel]

Relates to EMODnet/EMODnetWCS#53

[salvafern]

Apologies for the delay to comment on this. We will surely follow close as we are moving towards producing data products as multidimensional data cubes so it would be interesting to be able to read these through WCS - currently we are using ERDDAP.