Add Per Tensor Quantization Support to FXIRImporter (#55405)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55405
Pull Request resolved: https://github.com/pytorch/glow/pull/5516
Allows FXIRImport to import quantized model.
This diff doesn't include the supports for per-channel weights, linear and conv. Will address them in the next diff.
Test Plan: buck test glow/fb/fx/nnpi_importer:test_importer
Reviewed By: jackm321, jfix71
Differential Revision: D27313543
fbshipit-source-id: bf5c96ef5f2ff1835c09db981e0ceefaec56dd5b
