Add new cases to referrer trimming manual tests (#251)

Task URL: https://app.asana.com/0/856498667320406/1208699273169079/f

Add more manual cases, to test how referrer propagation works when opening new tabs from hyperlink or JS calls.

privacy-protections/referrer-trimming/index.html

@@ -23,6 +23,12 @@
             <li><a href="/come-back?testid=1p%20navigation">1p navigation</a></li>
             <li><a href="https://good.third-party.site/come-back?testid=3p%20navigation">3p navigation</a></li>
             <li><a href="https://bad.third-party.site/come-back?testid=3p%20tracker%20navigation">3p tracker navigation</a></li>
+            <li><a href="/come-back?testid=1p%20navigation" target="_blank">1p navigation [Target blank]</a></li>
+            <li><a href="https://good.third-party.site/come-back?testid=3p%20navigation" target="_blank">3p navigation [Target blank]</a></li>
+            <li><a href="https://bad.third-party.site/come-back?testid=3p%20tracker%20navigation" target="_blank">3p tracker navigation [Target blank]</a></li>
+            <li><button onclick="window.open('/come-back?testid=1p%20navigation')">1p navigation [JS window.open]</button></li>
+            <li><button onclick="window.open('https://good.third-party.site/come-back?testid=3p%20navigation')">3p navigation [JS window.open]</button></li>
+            <li><button onclick="window.open('https://bad.third-party.site/come-back?testid=3p%20tracker%20navigation')">3p tracker navigation [JS window.open]</button></li>
         </ul>
     </details>