Dependabot Snapshots has basic metadata about "status" and "reason"

[Ahmed3lmallah]

What are you trying to accomplish?

A snapshot is submitted from update-graph jobs, even if fail scenarios, such as:

• an empty snapshot when the manifest doesn't exist (deleted)
• an empty snapshot when an error is encountered

When those snapshots are consumed, it is hard to determine the reason behind having an empty snapshot without any supporting metadata! This PR adds those needed metadata:

• Failures: empty snapshot, status: failed, reason: #{error_type}
• Deleted manifest: empty snapshot, status: skipped, reason: "missing-manifest-files"
• Valid manifest with no dependencies: empty snapshot, status: ok
• Valid manifest with dependencies: regular snapshot, status: ok

Prerequisites:

• Adding Metadata to DependencySubmissionRequest model cli#551
• Updating graph smoke test to include metadata smoke-tests#360

How will you know you've accomplished your goal?

Start received dependency submissions with metadata

Checklist

• I have run the complete test suite to ensure all tests and linters pass.
• I have thoroughly tested my code changes to ensure they work as expected, including adding additional tests for new functionality.
• I have written clear and descriptive commit messages.
• I have provided a detailed description of the changes in the pull request, including the problem it addresses, how it fixes the problem, and any relevant details about the implementation.
• I have ensured that the code is well-documented and easy to understand.