Eliminate exceptions without message reaching api_return_error

[agners]

Description

The generic API handler api_return_error converts exceptions without message into "Unknown error, see supervisor". Such errors are not very useful to users, we should replace them with custom exception classes along with a user friendly message telling what is wrong.

Let's eliminate obvious/known cases where we raise Exceptions without messages first, then capture such events in Sentry to find other commonly occurring errors without messages.

Additional context

No response