feat: add support for Gremlin negated text predicates

[jakeboone02]

What does this PR do?

Adds support for Gremlin negated text predicates notContaining, notStartingWith, and notEndingWith.

How was it tested?

Local cargo test --all-features --workspace.

Community PR checklist

• No unsolicited architecture changes. New crates, new workspace dependencies, changes to grafeo-core/grafeo-engine internals, or new feature flags were either (a) requested in the linked issue or (b) discussed and approved in a GitHub Discussion before this PR was opened.
• No changes to shared infrastructure. CI workflows (.github/workflows/), the root Cargo.toml, codecov.yml, and scripts/ are not modified unless the change is the explicit purpose of this PR.
• No naming or concept conflicts. I have searched the codebase and existing issues/discussions to confirm that any new types, modules, or subsystem names do not duplicate or conflict with existing ones.

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Summary by cubic

Adds support for Gremlin negated text predicates: notContaining, notStartingWith, and notEndingWith. Enables negative substring, prefix, and suffix filters in has(), and removes redundant Gremlin tests.

• New Features
  • Lexer, parser, and AST recognize notContaining, notStartingWith, notEndingWith.
  • Translator emits logical NOT of Contains/StartsWith/EndsWith.
  • Expanded translator unit tests and engine/spec tests for has('prop', not...()) cases.

^{Written for commit 1d458c7. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 6 files

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[codspeed-hq]

Merging this PR will not alter performance

✅ 70 untouched benchmarks

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_{Comparing jakeboone02:feature/gremlin-negated-text-predicates (1d458c7) with main (4ebae02)}

[jakeboone02]

I had some trouble running tests locally, and I'm not sure why the Benchmark (PR) CI job failed, but otherwise I think this is ready to go.