* add batch_predict and initialized api for c
* add batch_predict and result str in C api
* modify visualization function
* add micro to add models batchify
* refactor and add models for ppdet others
* add base define
* add results api
* add headers
* add ppocr models
* add codes for implementing api
* add code
* add ppocr apis
* fix code
* add codes
* fix codes
* add demo