feat(hql): add schema field type validation

[ishaksebsib]

Description

This PR adds validation for field types in schema definitions to prevent the use of unknown or custom types (identifiers) in node, vector, and edge fields. It enforces the use of built-in types only.

Previously, invalid type definitions could still pass the Helix check

Related Issues

None

Checklist when merging to main

• No compiler warnings (if applicable)
• Code is formatted with rustfmt
• No useless or dead code (if applicable)
• Code is easy to understand
• Doc comments are used for all functions, enums, structs, and fields (where appropriate)
• All tests pass
• Performance has not regressed (assuming change was not to fix a bug)
• Version number has been updated in helix-cli/Cargo.toml and helixdb/Cargo.toml

Additional Notes

None