Move the 'create new campaign' button to the top

[CiellB]

There may have been a reason to have this at the bottom, but in busy times when there are 50+ campaigns on the campaign creator dashboard, it would be nice to have the "create a new campaign" button at the top or in a side bar, instead of having to scroll all the way down every time.

[mahmoud]

Agree, this is definitely something I'd like to see in the new UI. cc @Jayprakash-SE