Onnx2tf

- `NonMaxSuppression`
- Minor processing improvements

What's Changed
* nms fine-tuning by PINTO0309 in https://github.com/PINTO0309/onnx2tf/pull/51


**Full Changelog**: https://github.com/PINTO0309/onnx2tf/compare/1.2.11...1.2.12

- `NonMaxSuppression`
- Improved processing
- Avoiding FlexOP
- `NonMaxSuppressionV2` to `NonMaxSuppressionV4`
- [Bug in TFlite NonMaxSuppression 48](https://github.com/PINTO0309/onnx2tf/issues/48)
- https://github.com/tensorflow/tensorflow/issues/51629
- https://github.com/tensorflow/tensorflow/issues/52388

What's Changed
* Auto-padding bug fixed in NonMaxSuppression by Hyunseok-Kim0 in https://github.com/PINTO0309/onnx2tf/pull/50


**Full Changelog**: https://github.com/PINTO0309/onnx2tf/compare/1.2.10...1.2.11

- `NonMaxSuppression`
- Workaround for NonMaxSuppression bug in TensorFlow Lite. Migration to `NonMaxSuppressionV2`
- However, all NMS will be FlexOP. This is a silly fix, I know, but it is unavoidable to avoid output inconsistencies.
- https://github.com/tensorflow/tensorflow/issues/51629
- https://github.com/tensorflow/tensorflow/issues/52388
- [Bug in TFlite NonMaxSuppression 48](https://github.com/PINTO0309/onnx2tf/issues/48)

What's Changed
* [experimental] https://github.com/tensorflow/tensorflow/issues/51629 by PINTO0309 in https://github.com/PINTO0309/onnx2tf/pull/49


**Full Changelog**: https://github.com/PINTO0309/onnx2tf/compare/1.2.9...1.2.10

- `ConvTranspose`
- [simplify transposed convolution implementation 47](https://github.com/PINTO0309/onnx2tf/pull/47)

What's Changed
* simplify transposed convolution implementation by bas-aarts in https://github.com/PINTO0309/onnx2tf/pull/47


**Full Changelog**: https://github.com/PINTO0309/onnx2tf/compare/1.2.8...1.2.9

- Support for FreeYOLO E2E
- https://github.com/yjh0410/FreeYOLO
- https://github.com/PINTO0309/onnx2tf/releases/download/1.1.28/yolo_free_nano_crowdhuman_192x320_post.onnx
- Demo - FreeYOLO Nano 192x320 PINTO_special - Corei9 Gen.10 CPU

https://user-images.githubusercontent.com/33194443/207497782-f2266373-75e9-43a0-8740-dd733d8eaeb6.mp4

- `ConvTranspose`
- Supports padding attribute `NOTSET`.
- Fixed Abort bug when calling a conversion process from a Python script passing an ONNX graph via the `convert` method.

What's Changed
* handle NOTSET padding case for ConvTranspose op by bas-aarts in https://github.com/PINTO0309/onnx2tf/pull/45

New Contributors
* bas-aarts made their first contribution in https://github.com/PINTO0309/onnx2tf/pull/45

**Full Changelog**: https://github.com/PINTO0309/onnx2tf/compare/1.2.6...1.2.7