Quantization calibration refactor (#6893)
* Code refactor
* Modify code to tackle OOM when calibrating on larget dataset
* Fix mismatch issue when setting keepdims on ReduceMin/ReduceMax
* Add COCO val 2017 annotation
* Fix mismatch issue when setting keepdims on ReduceMin/ReduceMax
* Fix bug of "No module named:onnxruntime.quantization.CalTableFlatBuffers"
* Check and install flatbuffers module
* Add script to donwload coco dataset image and refactor example
* Fix bug of "No module
named:onnxruntime.quantization.CalTableFlatBuffers"
* Add CalTableFaltBuffers as module
* Remove annotation, user can download by themselves.
* Uncommet code
* Add back instances_val2017.json
* Make sure flatbuffers installed when ORT is installed
* Refactor code to call coco api
* Enable FP16 for example
