Job submission v2 with protocol using REST API

[abuccts]

What would you like to be added:

Upgrade to job submission v2 based on protocol yaml.

Why is this needed:

To improve job submission user experience and job protocol sharing in marketplace in the near future.

Without this feature, how does the current module work:

Use v1 version json config file.

Components that may involve changes:

Rest server and webportal.

Work items

• [Docs] Finalize protocol spec: Job submission v2 #2260.
• [Docs] Add new yaml files that follow new protocol:: [Docs] add new yaml files that follow pai protocol #2292.
• [Rest Server] Protocol yaml parsing, rendering, and validation: [Rest Server] Protocol yaml parsing, validation, and rendering #2274.
• [Rest Server] Convert protocol to framework launcher description file: [Rest Server] Convert protocol to framework launcher description #2291.
• [Rest Server] Refactor and update rest API v2: [Rest Server] Refactor and update rest API v2 #2329.
• [Webportal] Update job submission v2 form: Add protocol submission plugin #2461.

[scarlett2018]

@yanli2017 - may you help to review the #2292 ? @fanyangCS