Fix: pipeline gui editor issues

What does this MR do and why?

• Fix issue for empty configuration.
• Fix issue for not knowing where to save the work.
• Fix the issue that when deleting stage error occurs.
• Fix the issue that when configuration contains no stages the GUI won't render.
• Fix the issue that when click "Edit with GUI" the page won't direct to GUI tab.

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CleanShot_2024-07-09_at_13.51.30

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