Added copy button to link field (#216)

Co-authored-by: Adam Bem <adam.bem@zoho.eu>
Reviewed-on: #216
Reviewed-by: Mikolaj Widla <widlam@noreply.example.com>

Frontend/assets/css/tools/mock/r11tool.css

@@ -187,6 +187,11 @@ body {
     font-size: 20px;
 }
 
+.transparent-button {
+    background-color: #00000000;
+    border: #00000000;
+}
+
 .action-button.active {
     background: #2A93B0;
     border: 1px solid #7ed0eb;