feat(popup): pause Speeder per tab

extension/popup/popup.html

@@ -24,6 +24,12 @@
           type="button"
           aria-pressed="false"
         >Force last saved speed</button>
+        <button
+          id="pauseTab"
+          class="popup-compact-action"
+          type="button"
+          aria-pressed="false"
+        >Pause on this tab</button>
         <div class="popup-divider"></div>
         <div id="popupControlBar" class="popup-control-bar">
           <span id="popupSpeed" class="popup-speed">1.00</span>