Make email pattern work in new context

The email pattern looked a bit shonky when displayed in a narrower column. This
commit fixes it by making the email’s metadata (eg subject, from) into a table,
which it sort of is. This means that it is more flexible about the size of
container in which it sits.

app/assets/stylesheets/components/email-message.scss

@@ -7,9 +7,26 @@
     margin: 20px 0 10px 0;
   }
 
-  &-subject,
-  &-from {
-    margin: 10px 0;
+  &-meta {
+
+    @include core-19;
+    margin: 0;
+
+    td,
+    th {
+      @include core-19;
+      border-bottom: 0;
+      border-top: 1px solid $border-colour;
+    }
+
+    th {
+      color: $secondary-text-colour;
+    }
+
+    td {
+      width: 99%;
+    }
+
   }
 
   &-from {

app/assets/stylesheets/components/sms-message.scss

@@ -40,7 +40,7 @@
 .sms-message-use-links {
 
   @include copy-19;
-  margin-top: 55px;
+  margin-top: 52px;
 
   a {