Replacing sys.is_table_type SQL function with C implementation

[RuchaSK1]

Description

The SQL-based is_table_type() joins pg_type and pg_depend catalogs on every call. Replace with a C function using SysCache hash lookups and a narrow pg_depend probe, reducing per-call cost from milliseconds to microseconds.

Update sys.table_types_internal view to drop the pg_depend join and use the C function directly. This benefits sys.objects, sys.all_objects, and sys.tables which all depend on table_types_internal.

Issues Resolved

[List any issues this PR will resolve]

Test Scenarios Covered

• Use case based -

• Boundary conditions -

• Arbitrary inputs -

• Negative test cases -

• Minor version upgrade tests -

• Major version upgrade tests -

• Performance tests -

• Tooling impact -

• Client tests -

Check List

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