1. Remove fluid
2. Remove unused codes
2.1 remove adabert
2.2 remove ddpg controller of NAS
2.3 remove paddleslim.models
2.4 Remove PC-DARTS

* migrate remained api in common module

* fix bug
Co-authored-by: NBai Yifan <me@ethanbai.com>

* remove sensitive_pruner module

* migrate prune module

* fix some bug for migrating the prune module to 2.0-rc

* update some 1.8 api

* change num_worker from 16 to 1

* migrate common and core module

* fix a api in rl controller

* fix dataloader

* fix

* update

* fix

* fix

* update

* update

* fix

* fix win