feat: redesign python API #713

Is your feature request related to a problem? Please describe.
It is really hard to maintain due to two implementations.

Describe the solution you would like

• All the logic is in the top-level graphframes.py instead of being duplicated in connect / classic
• Naming convention should follow Python, not Scala (snake_case)
• Pregel and AM should be top-level classes without details of the implementation
• Connect / Classic should not contain logic, docs, etc., but should be just simple functions classes to proxy the py4j or protobuf

Component

• Scala Core Internal
• Scala API
• Spark Connect Plugin
• Infrastructure
• PySpark Classic
• PySpark Connect

Additional context
BREAKING CHANGES

I see it as a part of the planning 1.0 release.

Are you planning on creating a PR?

• I'm willing to make a pull-request