🗣 Description

Handle Error Messaging and VS Dashboard display for two specific Null Data use cases
CRASM-3008
CRASM-3267

💭 Motivation and context

As a user, I want to receive clear and informative error messages when data is missing or unavailable, so that I understand what went wrong and can decide on the next steps.

🧪 Testing

Use below acceptance criteria to determine how to test:

• If null data is encountered (but there is assets owned and hosts scanned):
• Display an error message that explains the issue in plain language.
• Display "--" instead of a 0 for assets owned or assets scanned if the organization is over 2 weeks old.
• Return standardized error messages.

📷 Screenshots (if appropriate)

If there are assets owned and hosts scanned and nothing else as a standard user and then as a admin or global view user

If there are assets owned and no hosts scanned and nothing else as a standard user and then as a admin or global view user

If there's even one vulnerability, the alert will disappear and the normal dashboard will appear.

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• All future TODOs are captured in issues, which are referenced in code comments.
• All relevant type-of-change labels have been added.
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated to reflect the changes in this PR.
• Tests have been added and/or modified to cover the changes in this PR.
• All new and existing tests pass.
• Bump major, minor, patch, pre-release, and/or build versions as appropriate via the bump_version script if this repository is versioned and the changes in this PR warrant a version bump.
• Create a pre-release (necessary if and only if the pre-release version was bumped).

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release (necessary if and only if the version was bumped).