Test262 TODO: TypedArray.prototype.sort

[rogeralsing]

Context: Fix Test262 failures for TypedArray.prototype.sort (including stability, -0 ordering, and comparefn exceptions).\n\nChanges:\n- Implement stable merge sort for TypedArray.prototype.sort to avoid List.Sort exception wrapping and preserve order when comparefn returns 0.\n- Keep original indices for stable ordering; add signed-zero ordering so -0 sorts before +0 for float typed arrays.\n- Avoid mid-sort out-of-bounds throws; write back only up to current length.\n\nTests:\n- dotnet test tests/Asynkron.JsEngine.Tests.Test262 -c Release --settings tests/Asynkron.JsEngine.Tests.Test262/BuiltInsTests.runsettings --filter "Name=TypedArray_prototype_sort"\n- dotnet test tests/Asynkron.JsEngine.Tests.Test262 -c Release --settings tests/Asynkron.JsEngine.Tests.Test262/BuiltInsTests.runsettings --filter "Name=TypedArray_prototype_sort_BigInt"\n