fix(kernel): preserve qualified interval parameter types - #514

Summary

• Preserve qualified interval parameter types such as INTERVAL MONTH and INTERVAL DAY in the kernel backend.
• Send parameters through the kernel's raw-parameter path, matching the Go driver.
• Add unit and end-to-end coverage for interval binding.

Merge order

1. Merge databricks-sql-kernel#298.
2. Update this branch to pin the merged kernel revision, then merge this PR.
3. Merge databricks-driver-test#1419, which re-enables the interval cases.

This draft intentionally leaves KERNEL_REV unchanged until the kernel PR merges.

Testing

• npm test -- tests/unit/kernel/positionalParams.test.ts tests/unit/kernel/execution.test.ts (83 passing)
• npx tsc --noEmit --project tsconfig.build.json
• npm run lint
• Prettier check on changed files
• Local Node → rebuilt kernel N-API → mock SEA run emitted {"ordinal":1,"type":"INTERVAL MONTH","value":"2-6"}

PECOBLR-4169