[DataTable] Fix multiselect containing commas (#9743)

When selected, multiselect filter options containing a comma would not
display any data because they were being split by commas (see below).

* Resolves #7531 
* On aces/CCNA#7962

Author: victori444

jsx/DataTable.js

@@ -370,8 +370,12 @@ class DataTable extends Component {
         searchKey = filterData[i].toLowerCase();
         searchString = data ? data.toString().toLowerCase() : '';
 
-        let searchArray = searchString.split(',');
-        match = (searchArray.includes(searchKey));
+        if (searchKey.includes(',')) {
+          match = (searchString == searchKey);
+        } else {
+          let searchArray = searchString.split(',');
+          match = (searchArray.includes(searchKey));
+        }
         if (match) {
           result = true;
         }