Notify invalid project-level configurations

[sacha-c]

Is your feature request related to a problem? Please describe.
When a project has an invalid toml configuration, it fails silently.

Describe the solution you'd like
If the project-level TOML is parseable but has errors

• Show errors or warnings in sheriff's logs. (should it be reflected in sheriff's exit code? 🤔 maybe not since this is really up to the project )
• If the project-level config gives a messaging channel to report to, include the specific errors in the report
• Include it somehow in the main report (like a little ⚠️ next to the project for example)

If the project-level TOML is completely unparseable

• Show errors or warnings in sheriff's logs. (should it be reflected in sheriff's exit code? 🤔 maybe not since this is really up to the project )
• Include it somehow in the main report (like a little ⚠️ next to the project for example)

Describe alternatives you've considered
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Additional context
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