Expose reflective QBS names

[ip332]

Summary

• Add public generic C APIs for QBS reflective string lookup and record, field, and enum type names.
• Reuse quarry_string_view_t with non-owning pointer/length semantics.
• Return clean statuses for unavailable minimal-QBS names, invalid indexes, invalid arguments, and malformed string-table state.
• Document lifetime and the fact that enum values remain numeric; no BRF printer or QBS format change is included.

Validation

• Complete CTest: 52/52 passed
• Generic C, QBS parser/serializer, traversal, packaging, and interoperability tests passed
• Strict C99 runtime build passed
• git diff --check passed

Quarry version: 0.1.30; QBS v1; BRF v2; generated-code compatibility epochs unchanged.