Xcube-cci

* Maintenance release to handle changes from external package

* Fixed retrieval of data sets with unsigned data types
(this affected SNOW datasets)
* Increased list of supported kerchunk datasets

* Fixed retrieval of time steps of BIOMASS datasets

* Improved support of vector data cubes
* Improved support of FIRE ECV datasets

* Migrated code from `ESA CCI Toolbox`. This encompasses the following changes:
* Added store aliases `esa-cdc` and `esa-climate-data-centre`, `esa-cci`
and `esa-cci-zarr`
* Added new data store `esa-cci-kc`
(and corresponding xcube data store `esa-cci-kc`) that allows performant
accessing of selected datasets of the ESA Climate Data Centre using a
Zarr view of the original NetCDF files. This approach is made possible by
using the [kerchunk](https://fsspec.github.io/kerchunk/) package. Also
added new Notebook that demonstrates usage of the new data store.
* Added opener `"datafame:geojson:esa-cdc"` to open data as data frames
* Added opener `"vectordatacube::esa-cdc"` to open data as vector data cubes
* Updated list of dataset states
* Set up pipeline to publish package on pypi

* Fixed support for climatology datasets