Created by: TomorrowIsAnOtherDay
To support for the computation framework with eager mode, we have discussed in our group and decided that parl should disentangle its abstraction classes (e.g, Model, Algorithm, Agent) with the computation framework. This PR has done the following points:
- define basic abstraction classes used for both eager mode and graph mode computation framework.
- move parl.framework into parl.core.fluid.
- add deprecated information for previous code.