Move banner_notification into after_header block

This moves the banner_notification from the top of the content block and into the bottom of the after_header block. This has the effect of moving the campaign bar above the global header bar - it looked odd when it was below it.

Arguably the banner notification should be above the user satisfaction survey because it's more important, but I didn't want to make that change now.
probably worth defining a new variable to use. Something along the lines of:

```erb
<% unless local_assigns[:hide_banner_notification] %>
```