Update cursor behavior in envelope-viewer.css

Changed the `cursor` property for `.sender-image-editor__field`
from `grab` to `move` and for its `:active` pseudo-class
from `grabbing` to `move`. This ensures consistent cursor
behavior when interacting with the element.

EnvelopeGenerator.Server/EnvelopeGenerator.Server/wwwroot/css/envelope-viewer.css

@@ -134,7 +134,7 @@
     padding: 0.2rem 0.3rem;
     text-align: left;
     line-height: 1.1;
-    cursor: grab;
+    cursor: move;
     display: flex;
     align-items: flex-start;
     justify-content: space-between;
@@ -143,7 +143,7 @@
 }
 
 .sender-image-editor__field:active {
-    cursor: grabbing;
+    cursor: move;
 }
 
 .sender-image-editor__field-label {