[CORE] Add type subsumption and object-ref containment relations

[tqchen]

This change:

• exposes type_subsumes_v<TargetType, SourceType> as the public target-first relation used for direct container storage reuse;
• adds object_ref_contains_v<RefType, ObjectType> for proving that raw object pointers can be wrapped without a runtime type check;
• updates GetRef, recursive container specializations, and focused compile-time and runtime coverage.

The separate names distinguish storage subsumption from object-ref containment while allowing direct variable-template specialization for typed refs.

[gemini-code-assist]

Code Review

This pull request refactors type trait checks in the TVM FFI library by replacing details::type_contains_v with type_subsumes_v and introducing object_ref_contains_v for safer object reference containment checks. The feedback highlights two critical template metaprogramming issues that could lead to hard compilation errors: first, the Tuple specialization of type_subsumes_v needs to safely handle mismatched pack sizes; second, object_ref_contains_v should be made SFINAE-safe to prevent compilation failures when instantiated with primitive or non-container reference types.

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