Add dss-standard module, which is three kind of basic request protocol to integrate with upper-layer application systems.

[wushengyeyouya]

What is the purpose of the change

Add dss-standard module, which is three kind of basic request protocol to integrate with upper-layer application systems.

Brief change log

• Defines the third-level development standard of AppConn, which used to integrate with third-party data application tools for workflow node management.
• Provide DSS standard commons module, adapt to the new architecture of DSS1.0.
• Defines the second-level development standard of AppConn, which used to integrate with third-party data application tools for project and role management.
• Defines the first-level development standard of AppConn, which used to integrate with third-party data application tools for SSO login.

close #373
close #372
close #371
close #370

[liuyou2]

thanks for this pr