Improve error messages that are emitted by tasks

What does this MR do?

Improves the error messages that are emitted by tasks. These include:

• Adding the status field to several error logs.
• Replacing generic error messages to be more specific, e.g. replacing error with client error or nothing with no content.
• Updated the tests to expect these new error logs.

Why was this MR needed?

Generic or vague error messages make it difficult to debug issues.

What's the best way to test this MR?

Run the various tests in the gitlab_test.go file that correspond to the changes made in the gitlab.go file and observe the logged error messages.

What are the relevant issue numbers?

Closes #6407 (closed)