Querying non-existent tables produces confusing error

[ceesem]

from caveclient import CAVEclient

datastack_name = 'minnie65_public'
client = CAVEclient(datastack_name)
client.materialize.get_table_metadata("some_nonsense_table_that_doesn't_exist")

should fail, but via an error that says the table does not exist. Instead, it fails with HTTPError: 500 Server Error: 'NoneType' object has no attribute 'pop' for url: https://minnie.microns-daf.com/materialize/api/v3/datastack/minnie65_public/version/795/table/some_nonsense_table_that_doesn't_exist/metadata. Various operations on table names (metadata, query table, etc) should validate that a table with that name exists and error in a clear way if not.