Add a bit of padding to make pathway links easier to click in the interaction tooltips

Now that the square parentheses are removed, the links are smaller and harder to click.  By adding padding, each link has a larger hit area.

Ref #1106 #1105

Author: maxkfranz

src/styles/common/cytoscape-tooltip.css

@@ -96,6 +96,7 @@
   & a {
     display: inline-block;
     margin-right: 10px;
+    padding: 0 0.5em;
   }
 }