Epic: system V2 features

[kvantricht]

This epic aims to list all necessary features still needed, improvements to be done and bugs to be fixed, in preparation of the release of system V2 from the processing module side.

• Reorganize extraction methods in src folder #263
• Geoparquet merging during or at the end of the extraction jobs #266
• Setup private extraction workflow #264
• Support single-point jobs (Remove spatial_extent argument in load_stac to support single point jobs #265)
• move UDP jsons from APEx back into WorldCereal repo #244
• Centrally organize public extractions geoparquets, combination of Phase II Glance extractions and Phase I existing extractions
• VDM UI to generate custom products worldcereal-vdm#3
• Revisit hierarchical classification options and summarize where we are #252
• Move and update process_parquet from presto-worldcereal #253
• System V2 demo notebooks #267
• Create a croptype UDP #258
• Manual backfilling of monthly/dekadal meteo composites #268
• Make a release of the package with proper version
• https://github.com/WorldCereal/worldcereal-capacitybuilding/issues/11
• Release a new version of gfmap on pypi and update dependencies

more tasks/issues will be added