need a inital name of stage in DevOps

Created by: shaowenchen

Describe the bug

There is not initial name provided to stage cause an error message.

Versions used(KubeSphere/Kubernetes) KubeSphere: 3.0.0

Expected behavior

give an initial name to stage, like stage-name-xxxxx

/area devops /milestone 3.0.0 /assign @harrisonliu5