[Model] update pptracking letterboxresize and add some comment (#438)

* add override mark

* delete some

* recovery

* recovery

* add tracking

* add tracking py_bind and example

* add pptracking

* add pptracking

* iomanip head file

* add opencv_video lib

* add python libs package

Signed-off-by: ChaoII <849453582@qq.com>

* complete comments

Signed-off-by: ChaoII <849453582@qq.com>

* add jdeTracker_ member variable

Signed-off-by: ChaoII <849453582@qq.com>

* add 'FASTDEPLOY_DECL' macro

Signed-off-by: ChaoII <849453582@qq.com>

* remove kwargs params

Signed-off-by: ChaoII <849453582@qq.com>

* [Doc]update pptracking docs

* delete 'ENABLE_PADDLE_FRONTEND' switch

* add pptracking unit test

* update pptracking unit test

Signed-off-by: ChaoII <849453582@qq.com>

* modify test video file path and remove trt test

* update unit test model url

* remove 'FASTDEPLOY_DECL' macro

Signed-off-by: ChaoII <849453582@qq.com>

* fix build python packages about pptracking on win32

Signed-off-by: ChaoII <849453582@qq.com>

* update comment

Signed-off-by: ChaoII <849453582@qq.com>

* add pptracking model explain

Signed-off-by: ChaoII <849453582@qq.com>

Signed-off-by: ChaoII <849453582@qq.com>
Co-authored-by: Jason <jiangjiajun@baidu.com>

examples/vision/tracking/pptracking/cpp/README.md

@@ -22,7 +22,6 @@ make -j
 wget https://bj.bcebos.com/paddlehub/fastdeploy/fairmot_hrnetv2_w18_dlafpn_30e_576x320.tgz
 tar -xvf fairmot_hrnetv2_w18_dlafpn_30e_576x320.tgz
 wget https://bj.bcebos.com/paddlehub/fastdeploy/person.mp4
-wget https://bj.bcebos.com/paddlehub/fastdeploy/person.mp4
 
 
 # CPU推理