[Web] Utilize full width, add new breakpoint

Signed-off-by: Kristian Feldsam <feldsam@gmail.com>

data/web/css/site/mailbox.css

@@ -21,6 +21,11 @@
   background: #F5F5F5;
 }
 @media (min-width: 992px) {
+  .container {
+      width: 100%;
+  }
+}
+@media (min-width: 1920px) {
   .container {
       width: 80%;
   }

data/web/css/site/quarantine.css

@@ -24,7 +24,12 @@
 
 @media (min-width: 992px) {
   .container {
-    width: 80%;
+    width: 100%;
+  }
+}
+@media (min-width: 1920px) {
+  .container {
+      width: 80%;
   }
 }