✨ [FEATURE]: Allow asset deletion within the button

[thinkjrs]

Is your feature request related to a problem? Please describe.

If a user uploads an asset via the Upload button erroneously during the campaign set up phase before submitting a campaign, the only way to remedy the issue situation is to refresh the page and redo the entire submission.

Describe the solution you'd like
We need to allow the users to click an "x" delete button, like users can do with campaigns in the Promo Dashboard list view.

Additional context
This is a highly-requested client feature.