[bug] CLI: improve visibility of kube auth errors

**Describe the bug**
An offshoot of the effort that we did in https://github.com/signadot/cli/pull/87.
The goal is to improve visibility of auth errors from kubectl

**To Reproduce**
Azure AD based kube auth + expiring refresh token

**Expected behavior**
Errors surfaced to user

**Observed behavior**
Errors swallowed completely, or sitting inside debug logs

**Additional context**
