Cleanup after update to scalajs-dom-2.8.0

The PR 'Add Navigator's ProtocolHandler methods #808'
scala-js/scala-js-dom#808
Was merged and release on this version of scalajs-dom

Author: FabioPinheiro

webapp/src/main/scala/fmgp/webapp/SandboxSettings.scala

@@ -15,15 +15,15 @@ object SandboxSettings {
         button(
           "Register URL protocol handler: web",
           onClick --> { _ =>
-            val n = dom.window.navigator.asInstanceOf[dom.NavigatorProtocolHandler]
+            val n = dom.window.navigator
             n.registerProtocolHandler("did", "#/resolver/%s")
             println("""registerProtocolHandler("did", "#/resolver/%s")""")
           },
         ),
         button(
           "Unregister URL protocol handler: web",
           onClick --> { _ =>
-            val n = dom.window.navigator.asInstanceOf[dom.NavigatorProtocolHandler]
+            val n = dom.window.navigator
             n.unregisterProtocolHandler("did", "#/resolver/%s")
             println("""unregisterProtocolHandler("did", "#/resolver/%s")""")
           },
@@ -41,15 +41,15 @@ object SandboxSettings {
         button(
           "Register URL protocol handler: web+did",
           onClick --> { _ =>
-            val n = dom.window.navigator.asInstanceOf[dom.NavigatorProtocolHandler]
+            val n = dom.window.navigator
             n.registerProtocolHandler("web+did", "#/resolver/%s")
             println("""registerProtocolHandler("web+did", "#/resolver/%s")""")
           },
         ),
         button(
           "Unregister URL protocol handler: web+did",
           onClick --> { _ =>
-            val n = dom.window.navigator.asInstanceOf[dom.NavigatorProtocolHandler]
+            val n = dom.window.navigator
             n.unregisterProtocolHandler("web+did", "#/resolver/%s")
             println("""unregisterProtocolHandler("web+did", "#/resolver/%s")""")
           },