simplify err messages in check function

[Siddhant-K-code]

Description

This pull request updates the error messages in the check function to provide more informative and concise error messages. The "failed to check" error message has been changed to "check failed" to better reflect the actual error.

Updated error message would look like:

Error: check failed: <error_message>

Actual Example:

Error: check failed: Post "http://localhost:8080/stores/01H4P8Z95KTXXEP6Z03T75Q984/check": dial tcp [::1]:8080: connect: connection refused

References

fixes #404

Review Checklist

• I have clicked on "allow edits by maintainers".
• I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• The correct base branch is being used, if not main
• I have added tests to validate that the change in functionality is working as expected

If you haven't done so yet, we would appreciate it if you could star the OpenFGA repository. :)

[ewanharris]

Thanks @Siddhant-K-code!