Alert design review

[corylown]

• Does it make sense for the alert to appear between the header and the masthead?
• Should there be some additional padding between the header and the alert box?
• The X to dismiss the alert looks odd. Can we add some padding and/or make it clearer it's actionable?

[marlo-longley]

Agree the padding and x-button could be improved, but wanted to say that the VT form is between the header and masthead, and that's specifically what I modeled this one on. Not that we have to stick to that, just some context.

[marlo-longley]

projectblacklight/blacklight#3153 was merged for the X button in Blacklight but we won't have access to the correct markup until a new release is shipped.

This ticket is 2/3 done, just waiting on the button release so we can style it properly.