handle long segment definition strings

frontend/src/admin/datamodel/components/database/MetadataTableList.jsx

@@ -71,7 +71,7 @@ export default class MetadataTableList extends Component {
         }
 
         return (
-            <div className="MetadataEditor-table-list AdminList">
+            <div className="MetadataEditor-table-list AdminList flex-no-shrink">
                 <div className="AdminList-search">
                     <Icon name="search" width="16" height="16"/>
                     <input

frontend/src/admin/datamodel/components/database/SegmentItem.jsx

@@ -22,7 +22,9 @@ export default class SegmentItem extends Component {
                     {segment.name}
                 </td>
                 <td className="px1 text-ellipsis">
-                    {description}
+                    <div style={{maxWidth: 400, overflow: 'hidden', textOverflow: 'ellipsis' }}>
+                        {description}
+                    </div>
                 </td>
                 <td className="px1 text-centered">
                     <ObjectActionSelect