Added email indicator icon, card menu style bugfix

no refs.
- added indicator icon to appropriately show which card is a newsletter email one
- fixed bug of card menu staying the same height when triggered via "/" menu

ghost/admin/app/styles/spirit/_koenig.css

@@ -858,7 +858,7 @@
 /* Chrome has a bug with its scrollbars on this element which has been reported here: https://bugs.chromium.org/p/chromium/issues/detail?id=697381 */
 .koenig-cardmenu {
     width: 272px;
-    height: 580px;
+    max-height: 580px;
     background-clip: padding-box;
     z-index: 9999999; /* have to compete with codemirror */
     left: -16px;

ghost/admin/lib/koenig-editor/addon/templates/components/koenig-card-email.hbs

@@ -1,5 +1,5 @@
  <KoenigCard
-    @icon="koenig/card-indicator-html"
+    @icon="koenig/card-indicator-email"
     @class={{concat (kg-style "container-card") " kg-email-card mih10 miw-100 relative"}}
     @style={{this.cardStyle}}
     @headerOffset={{this.headerOffset}}

ghost/admin/lib/koenig-editor/public/icons/koenig/card-indicator-email.svg

@@ -0,0 +1 @@
+<svg width="24" height="24" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title>Stroke 1</title><g stroke="#879BA3" fill="none" fill-rule="evenodd" stroke-linecap="round" stroke-linejoin="round"><path d="M3.875 5.75h16.25c.833 0 1.25.417 1.25 1.25v10c0 .833-.417 1.25-1.25 1.25H3.875c-.833 0-1.25-.417-1.25-1.25V7c0-.833.417-1.25 1.25-1.25zM15.072 10.312l3.178 2.938M8.927 10.312L5.75 13.25"/><path d="M21.067 6.178l-7.928 5.467c-.76.524-1.519.524-2.278 0L2.933 6.178"/></g></svg>