No result for puck 20

Just tried to load a sample from a puck and the service said no, which was an incorrect decision. Whilst investigating this, noticed that puck 20 did _not_ have a result in the returned data.

(in fact, I was trying to load to puck 10, the service incorrectly returned `None` for this location meaning neither a puck nor a lid was detected there)

The service should always return 20 statuses though, and an incorrect decision is one thing but not having the correct number is something else. The service should always return a status for all 20 pucks else consumers will probably get confused.

No file or test is named in the issue. Trace the Python service path that assembles returned puck statuses, then reproduce the sample-loading case described for puck 10 and puck 20. Done means the service returns exactly 20 statuses, including positions where neither a puck nor a lid is detected.

Written by the indexing model from the issue text.