As a Subscriber Specialist, I want to be able to provide a display URL separate from a landing page URL during campaign creation, so that I can better manage my ads

VALIDATE same as root destination URL, and other URL validation.

Not sure if this is a required separate story, or if this can be covered in "new ad creation" story.

If new ad, URLs should be re-used (pre-populated even?) if previously provided during merchant info creation.

If not provided, user should first input the display URL, which will auto-fill/copy the landing page URL

User is able to change the pre-filled in landing page URL

IF GOOGLE KEYWORD LEVEL URL is optional, then stop setting that (support issue when URL at keyword and campaign are different