Add MLIL function translation API

[tinysec]

Summary

• add the official Python-style MediumLevelILFunction.Translate convenience API
• provide a named per-instruction translation delegate with destination, source block, and source instruction
• preserve block labels, architecture/address state, source mappings, and writable return semantics
• dispose the partially built destination if a handler fails

Verification

• dotnet build --no-restore (0 warnings, 0 errors)
• external BinaryNinja E2E suite: 127/127 passed
• handler replacement, block ownership, instruction counts, and LLIL-to-MLIL translation maps verified