Add Header to Tenant section of top-bar fly-out
<span>[[= _.user.backend ]]</span>
</div>
<div class="divider"></div>
+ <div class="header">Your Tenants</div>
[[ if (_.tenants.length == 0) { ]]
<span class="dropdown odd">you have no tenants</span>
[[ } else { ]]
