[Feature][Manager] Fix bug in DolphinScheduler engine

[emptyOVO]

Description

The start() method in DolphinScheduler engine is never used, which cause it didn't correct manage the project in DS

• normaly when DS engine begin, it should create a project in DS, then handle process definition in this project, so start() method must be called before register(), unregister(), update() method, or the project code in DS will never be initialize correctly
  

Use case

No response

Are you willing to submit PR?

• Yes, I am willing to submit a PR!

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