fix(theme): use pointer cursor only on enabled buttons (#1300)

Author: Volker-E

src/client/theme-default/styles/base.css

@@ -148,8 +148,8 @@ button {
   background-image: none;
 }
 
-button,
-[role='button'] {
+button:enabled,
+[role='button']:enabled {
   cursor: pointer;
 }