Is your feature request related to a problem? Please describe.

Related to #4656.
At the moment we chain all error messages from plugins to a single, long, hard to understand error.
For example:

Error: failed to sync source aws: failed to fetch resources from stream: rpc error: code = DeadlineExceeded desc = failed to sync resources: failed to create execution client for source plugin aws: error retrieving credentials: failed to refresh cached credentials, no EC2 IMDS role found, operation error ec2imds: GetMetadata, canceled, context deadline exceeded

The error we want to report is actually just the aws: error retrieving credentials part

Describe the solution you'd like

The CLI should only report the relevant error for the user

Describe alternatives you've considered

N/A