BCDA 7581: Update import env files message to support ticket completion

[alex-dzeda]

🎫 Ticket

https://jira.cms.gov/browse/BCDA-7581

🛠 Changes

Improve utility of panic when trying to import env variables.

ℹ️ Context for reviewers

Current panic message is unhelpful, this adds debug info.

✅ Acceptance Validation

Change passes CI check

🔒 Security Implications

• This PR adds a new software dependency or dependencies.
• This PR modifies or invalidates one or more of our security controls.
• This PR stores or transmits data that was not stored or transmitted before.
• This PR requires additional review of its security implications for other reasons.

If any security implications apply, add Jason Ashbaugh (GitHub username: StewGoin) as a reviewer and do not merge this PR without his approval.