Implement Pangeo notebooks

[tinaok]

Identify the notebooks from pangeo-openeo-BiDS-2023/tutorial /part3 Update and implement them.

[annefou]

for now I worked on the data access using Pangeo approach and created the corresponding notebooks for the "Data Access" section. See https://github.com/annefou/cubes-and-clouds/tree/main/lectures/2.3_data_access/exercises/_alternatives

[annefou]

Also added & tested snow cover on Pangeo@EOSC:

• Jupyter notebook: https://github.com/annefou/cubes-and-clouds/blob/main/lectures/3.1_data_processing/3.1_exercises/_alternatives/31_data_processing_pangeo.ipynb
• Rendered notebook: https://annefou.github.io/cubes-and-clouds/3.1_data_processing/3.1_exercises/_alternatives/31_data_processing_pangeo.html

We would need to test it on EOX and better integrate it into the EO-College course.

[clausmichele]

@annefou thanks for the PR! I now had finally time to go through them and I have a couple of feedbacks and thoughts:

• Filtering with the cloud cover is also possible directly when querying the STAC Catalog. Do you think it's worth to mention or not? Notebook https://github.com/annefou/cubes-and-clouds/blob/main/lectures/2.3_data_access/exercises/_alternatives/pangeo_data_access_filter.ipynb Code to do that:

  
  URL = "https://earth-search.aws.element84.com/v1"
  catalog = pystac_client.Client.open(URL)
  items = catalog.search(
  bbox=spatial_extent,
  collections=["sentinel-2-l2a"],
  query={"eo:cloud_cover":dict(lt=50)}
  ).item_collection()

datacube = stackstac.stack(items, bounds_latlon=spatial_extent, ) datacube

- In the `reduce` notebook https://github.com/annefou/cubes-and-clouds/blob/main/lectures/2.3_data_access/exercises/_alternatives/pangeo_data_access_reduce.ipynb there is still the openEO process `reduce_spatial` mentioned. Additionally, the `groupby` method is mentioned at the beginning but never used. Maybe it would be interesting to show various approaches? The [xarray.DataArray.reduce](https://docs.xarray.dev/en/stable/generated/xarray.DataArray.reduce.html) is also valid and has the same name as in openEO.

[clausmichele]

Also added & tested snow cover on Pangeo@EOSC:

* Jupyter notebook: https://github.com/annefou/cubes-and-clouds/blob/main/lectures/3.1_data_processing/3.1_exercises/_alternatives/31_data_processing_pangeo.ipynb

* Rendered notebook: https://annefou.github.io/cubes-and-clouds/3.1_data_processing/3.1_exercises/_alternatives/31_data_processing_pangeo.html

We would need to test it on EOX and better integrate it into the EO-College course.

It looks really good, I like how you improved it compared to the old version.