Improve CoverageJSON Ecosystem 3: GDAL driver

[chris-little]

3. A GDAL CoverageJSON Read and Create driver, supporting the GDAL multidimensional array API. This would allow conversion to and from other multidimensional array types (NetCDF, Zarr) using gdalmdimtranslate, and easier uptake in OSGeo software building on GDAL.

[chris-little]

@edzer thinks it easiest to write in C++ rather than Python or C. The NetCDF, Zarr and MEM driver implementations could work as examples.