Update company logo and CSS classes in UI config

Changed the company logo source from digital_data.svg to wisag.svg.
Updated associated CSS class names to use wisag-specific
identifiers for show and locked states.

EnvelopeGenerator.Web/appsettings.UI.json

@@ -114,10 +114,10 @@
       }
     },
     "Company": {
-      "Src": "/img/digital_data.svg",
+      "Src": "/img/wisag.svg",
       "Classes": {
-        "Show": "dd-show-logo",
+        "Show": "wisag-show-logo",
-        "Locked": "dd-locked-logo"
+        "Locked": "wisag-locked-logo"
       }
     }
   },