Allow zooming in WebView

Note that this does not force-enable zooming on pages with set viewports (which typically implies proper mobile scaling).
Closes #8588

core/src/main/java/eu/kanade/tachiyomi/util/system/WebViewUtil.kt

@@ -40,6 +40,11 @@ fun WebView.setDefaultSettings() {
         useWideViewPort = true
         loadWithOverviewMode = true
         cacheMode = WebSettings.LOAD_DEFAULT
+
+        // Allow zooming
+        setSupportZoom(true)
+        builtInZoomControls = true
+        displayZoomControls = false
     }
 }