Improve error message for unauthorized launches

[JaimeSeqLabs]

Description

When a user with Launch role tries to launch a new pipeline using URL the resulting error message is confusing and non-descriptive.

A Launch user does not have permission to create a new pipeline from a URL and launch it, so the failure is expected. However, the error message should mention the cause of the failure: the insufficient role level. Instead, the error message is:

 ERROR: Unknown. Check that the provided identifier is correct.

Steps to reproduce

1. As an admin user: create an organization, workspace and valid compute environment marked as "primary"
2. Add a new user as participant to the workspace with role Launch
3. As a launch user: setup a new tower access token to use the CLI
4. Try launching a new pipeline from URL in the workspace as launcher user:

$> tw launch launch https://github.com/nextflow-io/hello -w Org/Wsp

5. The launch attempt should fail with:

 ERROR: Unknown. Check that the provided identifier is correct.

6. If there is already a pipeline created by admin user the launch user should be able to launch it by name as usual:

$> tw launch launch TestHello -w Org/Wsp

Suggested fix

Capture the ApiException thrown and check the http response code. If the code is 403 add "role insufficient" to the resulting error msg.