Address review: pin visited title link colour (issue #4931xxx)

Guard the title anchor against global a:visited author rules bleeding
the browser visited-link colour into the title text.

Author: adamwoodnz

client/my-sites/stats/videopress-stats-module/style.scss

@@ -101,6 +101,10 @@
 				font-size: $font-body-small;
 				font-weight: 500;
 				text-decoration: none;
+
+				&:visited {
+					color: var(--color-text);
+				}
 			}
 
 			&::before {