Redefine collection-level metadata and v0.3.0

[m-mohr]

Related Issue(s): #13 #40 #26 #34 #35 #36

Notes:

• CI fails as the fiboa CLI hasn't been updated yet.
• The geoparquet examples is not up-to-date due to the same reason.
• Discussion point: GeoJSON encoding - null vs omit property
• schemas per collection - how to approach this, probably make schemas a special field, not per feature and switch from list to object

Proposed Changes:

1. see Changelog

PR Checklist:

• This PR has no breaking changes.
• I have added my changes to the CHANGELOG
  or a CHANGELOG entry is not required.

[m-mohr]

One example for FTW: fiboa/cli#92

[cholmes]

Generally looks good, happy to approve and get this in and evolve as things go. But I do think it's likely now worth explaining a bit more what a 'collection' is conceptually, and explain a bit about merging, and things moving from collection to feature level, and potentially back up. I don't think this needs to be a ton, just enough for people to make sense of how to think about a collection and what properties to put there vs. not

[m-mohr]

Discussion results:

• Collection id required
• Dictionary with Schemas per Collection id
• Merge:
  • People select columns in CLI
  • geometry CRS Needs to be harmonized
  • disallow null in GeoJSON
• Parquet: don't add best practice to add json file
• CLI: Separate create stac command
• FeatureCollection: collection-level data on the top-Level

[m-mohr]

@cholmes Do you want to do your final review?