Add refresh button to envelope UI when not read-only

A "Refresh" button with a counterclockwise arrow icon is now shown in the envelope UI, but only when the envelope is not in read-only mode. The button uses standard styling classes for consistency.

EnvelopeGenerator.Web/Views/Envelope/ShowEnvelope.cshtml

@@ -43,12 +43,14 @@
             </svg>
             <span>@_localizer.Reject()</span>
         </button>
+        @if(!Model.Envelope!.ReadOnly){
         <button class="btn_refresh btn btn-secondary btn-desktop" type="button">
             <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" fill="currentColor" class="bi bi-arrow-counterclockwise" viewBox="0 0 16 16">
                 <path fill-rule="evenodd" d="M8 3a5 5 0 1 1-4.546 2.914.5.5 0 0 0-.908-.417A6 6 0 1 0 8 2v1z" />
                 <path d="M8 4.466V.534a.25.25 0 0 0-.41-.192L5.23 2.308a.25.25 0 0 0 0 .384l2.36 1.966A.25.25 0 0 0 8 4.466z" />
             </svg>
         </button>
+        }
     </div>
     }    
     <div class="dd-cards-container">