Co-authored-by: Øystein Olai Heggen <[email protected]>

The code used to combine the chunks in upload order rather than
block_index order. This commit fixes this issue.

- Add observationOut helper function
- Refactor experiment/prioirs
- Add helper function to Update endpoint
- Make use of ensemble_ids
- Change relative import to absolute
- Fix priors into new_record_matrix

- Migrate prior endpoint tests into experiment
- Add get single experiment endpoint

SQLAlchemy complains about cache_ok not existing in UUID and spamming me
with warnings. We tell it that UUID is cacheable and that it's all fine.

The `Metadata` field that points to the `_metadata` column in SQL used
to be auto-generated by the Graphene-SQLAlchemy package. Now there's
only the `userdata` field. Further, this commit removes the
`metadata_dict` property in favour of having the column default to `{}`.

Modify testclient post, get, .. to comply with requests types

…ntics

This reverts commit aaccf35.

This reverts commit 2995218.

This reverts commit 21c64d2.

This reverts commit 0bae073.

This reverts commit 9e86992.

These replace client.Session with versions that:
1. Cache a global connection information
2. Accept a `ConnInfo` object so that we don't have to create files or
   set environment variables.
3. Look for `storage_server.json` in any parent directory

fastapi had breaking change in 0.74.0 where we now need to
specifically handle only exceptions related to our database
transaction.
https://fastapi.tiangolo.com/release-notes/#breaking-changes

Endpoint gives info about server, for now only a name.

This drops the requirement of having an external provider of the ERT
Storage API. One day we may resurrect ert-storage as an entirely
separate service, but as of today only dark_storage should be supported.