TOSA reference model v0.50.0 release tag

- Note that in this release, the specification has added the concept of
levels, but the reference model and conformance tests do not support
testing of levels
- Added FP16 and BF16 data type support, renamed FLOAT to FP32
- Started support for TOSA Main Inference conformance. Still a work in
progress
- Added the IModelRunner interface to allow running the reference model
via an API
- Added simple testing against Numpy
- Tests created/fixed: prelu, CAST, RESCALE, TILE, SIGMOID
- Upgraded Eigen submodule to version 3.4.0
- Misc. bugfixes
  1. ba5fad3 Add IModelRunner interface to TOSA Reference Model by Matthew Sloyan · 1 year, 9 months ago[Renamed (99%) from reference_model/src/func_debug.h]
  2. 286f834 Simplify the argument parsing and debug code by Eric Kunze · 2 years ago
  3. 903763c Add SUBGRAPH_ERROR_IF() to catch graph-level error. by Kevin Cheng · 2 years, 9 months ago
  4. acb550f Replace node level check ASSERT_MSG_NODE()/FATAL_ERROR_NODE() with REQUIRE() or ERROR_IF() by Kevin Cheng · 3 years ago
  5. e5e2676 Initial checkin of TOSA reference_model and tests by Eric Kunze · 3 years, 9 months ago