test(pt_expt): move fparam/aparam inference tests to test_deep_eval.py

Move default_fparam and aparam tests from test_dp_freeze.py (freeze
entrypoint tests) to test_deep_eval.py (inference tests) where they
belong. Add .pte and .pt2 test classes for both, with consistency
checks against eager model forward and cross-format comparison.

Author: Han Wang