Add some margin on the TableRow score column (#669)

The TableRow currently has some margin on the left, but not on the
right. This is visually unbalanced, especially when expanded so depth>0,
as the content on the right is at the very edge of the shaded rectangle.

This commit cleans that up a bit!

Test plan: Visual inspection (see screenshots in the pull request). I
don't think unit tests are necessary for small visual tweaks like this.

src/app/credExplorer/pagerankTable/TableRow.js

@@ -70,7 +70,9 @@ export class TableRow extends React.PureComponent<
             {description}
           </td>
           <td style={{textAlign: "right"}}>{percent}</td>
-          <td style={{textAlign: "right"}}>{scoreDisplay(score)}</td>
+          <td style={{textAlign: "right"}}>
+            <span style={{marginRight: 5}}>{scoreDisplay(score)}</span>
+          </td>
         </tr>
         {expanded && children}
         {showPadding && <PaddingRow backgroundColor={backgroundColor} />}