Save workflow - Improve user experience for naming new workflow file

[schoinh]

Use Case

On my first time using the "Save workflow" button to save a workflow, I specified the workflow file name as "sec61_workflow" (I didn't input "sec61_workflow.json" because I thought .json was already specified in the box below), and I got this error upon saving: "ValueError: Workflow configuration file save path must have a .json extension."

Solution

The above error message makes sense to me as a developer but for general users we should have an actual error message pop up (instead of a console error that makes it look like they broke something). OR we just attach a .json extension to the end of the file name specified if they didn't specify anything.

[Aerendel]

As discussed, we want to:

• Put in .json filename placeholder
• Attach .json to the filename if no extension provided or another extension