Before this change we loaded databases eagerly when a serverID was
passed on startup BEFORE starting up the gRPC server. Since loading
(esp. at its current state without checkpoints and with too many small
parquet files) can take very long, K8s thinks IOx is unhealthy. With
this change we are now loading databases in the server background worker
once a serverID is available. Until then we block all DB-related
interactions including adding new databases (since without inspecting
the object store there is now way we can check if the DB already
exists).
Furthermore we now load database no matter if the serverID was passed on
startup (via CLI or environment variable) or was set later via gRPC
call. Before this change the latter case was somewhat forgotten.
* refactor: pull Scenario code out of main module
* refactor: break out http into tests
* refactor: use random org_id and bucket_id
* refactor: port read_api to be indepndent
* refactor: port last test
* refactor: convenience methods to create different clients in end-to-end tests
* fix: improve comments
Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>