Fix footer overlapping booking calendar

Rise the transaction details section on top of the footer so that the
booking dates calendar won't go below it.

src/components/TransactionPanel/TransactionPanel.css

@@ -180,6 +180,7 @@
     background-color: var(--matterColorLight);
     border: 1px solid var(--matterColorNegative);
     border-radius: 2px;
+    z-index: 1;
   }
 }