Refactor lite serializer dependencies from full jit (#42127)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42127
This diff renames core_autograd_sources to core_trainer_sources and moves/adds dependencies for the lite trainer in order to build the serializer functionality internally.
ghstack-source-id: 108589416
Test Plan: Manually tested serializer functionality from the internal lite trainer and verified that data is written correctly.
Reviewed By: iseeyuan
Differential Revision: D22738293
fbshipit-source-id: 992beb0c4368b2395f5bd5563fb2bc12ddde39a1
