fix(compiler): preserve proto package info in IR type lookup and validation

[BaldDemian]

Why?

Current Fory compiler's translator and validator for protobuf cannot handle the package information correctly. All four newly-added test cases in test_proto_frontend.py would fail in the current version, despite they are all verified by protoc (should reject / should accept).

What does this PR do?

• Introduce a new package field to the Message, Enum, and Union types in the Fory IR AST. For .fbs and .fdl inputs, this field is always None. During protobuf translation, type looking-up and validation, the package information is utilized and enforced.

• Define testcases accordingly. Actually this fix is test-driven.

Related issues

N/A.

AI Contribution Checklist

• Substantial AI assistance was used in this PR: yes / no
• If yes, I included the standardized AI Usage Disclosure block below.
• If yes, I can explain and defend all important changes without AI help.
• If yes, I reviewed AI-assisted code changes line by line before submission.
• If yes, I ran adequate human verification and recorded evidence (checks run locally or in CI, pass/fail summary, and confirmation I reviewed results).
• If yes, I added/updated tests and specs where required.
• If yes, I validated protocol/performance impacts with evidence when applicable.
• If yes, I verified licensing and provenance compliance.

AI Usage Disclosure

• substantial_ai_assistance: yes
• scope: bug-fix suggestions, compiler code structure clarification
• affected_files_or_subsystems: compiler/fory_compiler/frontend/proto/translator.py, compiler/fory_compiler/ir/ast.py, compiler/fory_compiler/ir/validator.py
• human_verification: I have run the tests locally and review the changes
• performance_verification: N/A
• provenance_license_confirmation: Apache-2.0-compatible provenance confirmed; no incompatible third-party code introduced

Does this PR introduce any user-facing change?

N/A.

Benchmark

N/A.

[BaldDemian]

Current fix cannot handle some complex cases properly, still working on it