Display Warning Message if Project Submission Fails

[DanielJDufour]

Is your feature request related to a problem? Please describe.
When doing local development, I tried to upload a project, but it failed. I had incorrectly set the odk_central_url to "odk.fmtm:7050" and got back an error message: "URL scheme should be 'http' or 'https'['body', 'odk_credentials', 'odk_central_url']". However, I didn't see any error message on the screen, indicating to me that the upload attempt had happened and that there was an error.

Describe the solution you'd like
It would be ideal if an error message were displayed on the screen. Additionally, it would be good to add extra validation when entering the odk credentials to validate if the odk_central_url starts with http:// or https://.

Describe alternatives you've considered
Leave as is

Additional context
This isn't urgent, so definitely no rush.

Thank you!