Add document title in topbar and allow params with user extensions (#720)

* use document title to display the current file
* add document title in top bar

src/editor/ConfigObj.js

@@ -351,6 +351,7 @@ export default class ConfigObj {
       const cached = this.editor.storage.getItem(name)
       if (cached) {
         this.editor.loadFromString(cached)
+        this.editor.topPanel.updateTitle(this.editor.storage.getItem(`title-${name}`) ?? 'untitled.svg')
       }
     }