Diagnostic bug fixes (and snapshot tests)

[matthewnitschke-wk]

Added some rough snapshot tests for the diagnostics functionality that was recently added #98

When adding these, it was discovered that the reported diagnostics were not accurate, and there was a core bug in its implementation (using the wrong offset when finding which error was associated with the symbol). This bug was fixed in this PR as well

[aviary3-wk]

Security Insights

No security relevant content was detected by automated scans.

Action Items

• Review PR for security impact; comment "security review required" if needed or unsure
• Verify aviary.yaml coverage of security relevant code

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Questions or Comments? Reach out on Slack: #support-infosec.

[matthewnitschke-wk]

Quick and dirty solution to snapshots for diagnostic data. I'd prefer the source annotation approach that scip snapshot implements

Considering either contributing back to scip snapshot or just implementing a custom solution to this problem, but in the meantime this will let us track changes to diagnostics

[matthewnitschke-wk]

the specific node we pass in here isn't always the offset of the specific entity. For example, some elements are indexed by some analyzed element instead of the ast node at the specific depth

For this reason, just pass the offset as an int, so the errors can be correctly calculated where necessary

[matthewnitschke-wk]

QA +1

• new diagnostic snapshot tests are technically missing a few results, but this is a huge improvement on the results that we are currently seeing

[matthewnitschke-wk]

🚀 @Workiva/release-management-p 🚢

[rmconsole-wf]

+1 from RM

[matthewnitschke-wk]

Closes #98