Unify selects on bakers

[lassemand]

Issue:
Many queries towards bakers differ in behaviour, but in the end how the baker looks like in terms of select remains the same.

Possible solutions to be investigated:

• Investigate if sqlx supports mapping from resource to select in any sense
• Use compile time checked queries, so we can split up and compose the queries, but I think this becomes prone to errors, and we would need more testing to catch mistakes, which is probably more cumbersome.
• Fetch ids in this query and then have another query, which fetches from a list of ids, meaning we only list every selected field in one query. Here it would mean a hit in performance instead, but I am not sure how much though, so it might be worth it.

Comment: This may also be an issue on other resources, however it was currently only detected on bakers