[CLI-1454] Modify potentially misleading flag suggestions

[Steven Gagniere (sgagniere)]

Checklist

1. [CRUCIAL] Is the change for CP or CCloud functionalities that are already live in prod?
   • yes: ok

What

Trying to run api-key store x x without an active cluster and without the --resource flag gives a suggestion to pass --cluster or --resource, but --cluster is not an allowed flag for this command.

I've modified api-key store to discard the error from GetKafkaClusterForCommand() and instead return an error with a suggestion tailored to this command (which was already being used further down).

On a survey of kafka, connect, ksql and pipeline commands, which all have the potential to see this same error message, none of them as far as I can tell accept --resource as a valid flag, so the suggestion is also misleading for these commands and their subcommands.

Based on that, I've changed the suggestion back to a previous version which only suggested the --cluster flag. Other api-key commands either have --resource marked as REQUIRED or else don't need a resource or cluster, so this shouldn't result in more misleading errors.

References

https://confluentinc.atlassian.net/browse/CLI-1454

Test & Review

Tested manually and ran all tests