[Static Runtime] Implement aten::append (#63350)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/63350
Add a native implementation for `aten::append`, the list append op.
Test Plan: New unit test: `buck test caffe2/benchmarks/static_runtime:static_runtime_cpptest -- Append`
Reviewed By: hlu1
Differential Revision: D30326461
fbshipit-source-id: 0dbdf6cc82e78c7c36db39583256f6b87385e3d3