[QUANTIZE] Refactor quantization codebase and fix model accuracy

[ZihengJiang]

A mirror PR of #3543 due to CI error.

• Separate quantization code base into different files: partition.cc, annotate.cc, realize.cc
• Change rewrite_for_vta to extra partition pass and enable it by default
• Change annotation.force_cast(x) to annotation.cast_hint(x, dtype)
• Remove qconfig.store_lowbit_output and enable it by default
• Fixed accuracy of models like mobilenet：
  • resnet18_v1(8-16bit): 69.29%
  • resnet18_v1(8-32bit): 69.29%
  • resnet34_v1: 73.33%
  • resnet50_v1: 74.78%
  • resnet101_v1: 75.66%
  • mobilenetv2_1.0: 66.64%

[tmoreau89]

@nhynes do you happen to know why the rust CI error is occurring on this PR? Thanks!