refactor!: finish parser migration

Finally! :)

This removes all code related to the old parser.

#65

lib/parser/classes/NavigatableText.js

@@ -0,0 +1,26 @@
+'use strict';
+
+const Text = require('./Text');
+const NavigationEndpoint = require('./NavigationEndpoint');
+
+class NavigatableText extends Text {
+  type = 'NavigatableText';
+  endpoint;
+  constructor(node) {
+    super(node);
+    // TODO: is this needed? Text now supports this itself
+    this.endpoint =
+            node.runs?.[0]?.navigationEndpoint ?
+              new NavigationEndpoint(node.runs[0].navigationEndpoint) :
+              node.navigationEndpoint ?
+                new NavigationEndpoint(node.navigationEndpoint) :
+                node.titleNavigationEndpoint ?
+                  new NavigationEndpoint(node.titleNavigationEndpoint) : null;
+  }
+
+  toJSON() {
+    return this;
+  }
+}
+
+module.exports = NavigatableText;