Proposal: Graphical page realizes "Parametric Build"

Due to some technical limits, the parameters we entered when creating the "Parametric Build" pipeline can only take effect in `config.xml`, and the Jenkinsfile generated when the pipeline is drawn cannot get the parameters configured when it is created, so it's difficult to use the graphical page Elegantly create "Parametric Build" pipelines.

I think it is possible to directly provide the "Parametric Build" entry when drawing the pipeline, and remove the "Parametric Build" entry at creating the pipeline, then "Parametric Build" can be perfectly realized and never confuse users anymore.



/kind proposal
/area devops
/area console

Start by tracing the graphical pipeline creation and drawing flows, then inspect how config.xml and the generated Jenkinsfile handle parameters. The change is complete when Parametric Build is available while drawing the pipeline, is removed from pipeline creation, and configured parameters are reflected in the generated Jenkinsfile.

Written by the indexing model from the issue text.