Add conversion method from TomlConfigLoader to NetworkConfig to enhance configuration experience (#990)

* add method to create NetworkConfig from TomlConfigLoader
* allow web export/import toml config file and gui edit toml config
* Extract the configuration file dialog into a separate component and allow direct editing of the configuration file on the web

easytier-gui/src/App.vue

@@ -8,5 +8,6 @@ onBeforeMount(async () => {
 </script>
 
 <template>
+  <Toast position="bottom-right" />
   <RouterView />
 </template>