[EPIC] Cleanup of stac builder code

[VictorVerhaert]

This issue serves as an overview of changes to make to the stac builder to clean up the code.
It's goal is to make the builder easier to understand, debug and expand.

• use pyproject.toml as only dependency source to prevent inconsistent environments (terracatalogue might need a seperate init for this)
• make terracatalogue depedency optional
• Use the AssetMetadata as the generic interface for all the data that needs to be extracted out of sources. After this al generic behaviour should be able to be implemented by using custom callbacks. This allows for a lot of code to be removed improving readability.
• [optional/discussion needed] move all the arguments to the config file so one workflow could in theory be used for all collections that do not need custom item postprocessors. (This would allow for easily rebuilding all collections should a bug be found in the builder)
• remove backup code for saving to geoparquet and dataframes as this is not being used for debugging and complicates the code
• cleanup TODO's (currently 95 in total) -> either create an issue for it and link it in the code, directly fix it or deem the todo unnecessary
• remove docker functionality (was this ever used?)
• remove makefile funtionality -> setting up environments should not be the responsibility of the stac builder and should be easy with the pyproject.toml, the makefiles for building collections are not being used or up to date
• running extra linting tools on the source code (similar to the openeo-python-client)
• Update the documentation (most of it is outdated)
• Update the template for new collections -> keep this up to date with new collections being build
• better determine collection metadata from items (item_assets, summaries)