refactor!: finish parser migration

Finally! :)

This removes all code related to the old parser.

#65

lib/parser/classes/comments/CommentThread.js

@@ -0,0 +1,74 @@
+'use strict';
+
+const Parser = require('../..');
+const { InnertubeError } = require('../../../utils/Utils');
+
+class CommentThread {
+  type = 'CommentThread';
+
+  #replies;
+  #actions;
+  #continuation;
+
+  constructor(data) {
+    /** @type {import('./Comment')} */
+    this.comment = Parser.parse(data.comment);
+    this.#replies = Parser.parse(data.replies);
+    /** @type {boolean} */
+    this.is_moderated_elq_comment = data.isModeratedElqComment;
+  }
+
+  /**
+   * Retrieves replies to this comment thread.
+   * @returns {Promise.<CommentThread>}
+   */
+  async getReplies() {
+    if (!this.#replies)
+      throw new InnertubeError('This comment has no replies.', { comment_id: this.comment.comment_id });
+
+    const continuation = this.#replies.contents.get({ type: 'ContinuationItem' });
+    const response = await continuation.endpoint.callTest(this.#actions);
+
+    this.replies = response.on_response_received_endpoints_memo.get('Comment').map((comment) => {
+      comment.setActions(this.#actions);
+      return comment;
+    });
+
+    this.#continuation = response.on_response_received_endpoints_memo.get('ContinuationItem')?.[0];
+
+    return this;
+  }
+
+  /**
+   * Retrieves next batch of replies.
+   * @returns {Promise.<CommentThread>}
+   */
+  async getContinuation() {
+    if (!this.replies)
+      throw new InnertubeError('Continuation not available.');
+
+    if (!this.#continuation)
+      throw new InnertubeError('Continuation not found.');
+
+    const response = await this.#continuation.button.endpoint.callTest(this.#actions);
+
+    this.replies = response.on_response_received_endpoints_memo.get('Comment').map((comment) => {
+      comment.setActions(this.#actions);
+      return comment;
+    });
+
+    this.#continuation = response.on_response_received_endpoints_memo.get('ContinuationItem')?.[0];
+
+    return this;
+  }
+
+  /**
+   * @param {import('../../../core/Actions')} actions
+   * @private
+   */
+  setActions(actions) {
+    this.#actions = actions;
+  }
+}
+
+module.exports = CommentThread;