Change button 'Edit' to be 'Submit' on test edit screen

[dividor]

Describe the bug
We say 'Submit' on all other forms, this is to make the test form the same

To Reproduce
Steps to reproduce the behavior:

1. Run DOT UI
2. Go to Configuration > Tests
3. Click on a test
4. Note button says 'Edit' not 'Submit'

Additional context
Be aware that this form is overloaded and supports bot Edit and Add. be careful if changing the label, that there are no impacts with field conditionality