Updates and extends TestNNDeviceType (pytorch#26638)

Summary:
- Moves several tests to TestNNDeviceType
- Merges helper base with TestNNDeviceType
<s>- Enables non-default stream for TestNN (like recent updates to TestTorch and TestCUDA)</s>

Reverted non-default stream due to failure of test_variable_sequence_cuda (main.TestNN).
Pull Request resolved: pytorch#26638

Differential Revision: D17543899

Pulled By: mruberry

fbshipit-source-id: 001fa191f5fe424f2e7adc378b8fb5ee7f264f16

Author: Mike Ruberry