moved timeline undoable commands to using the new NodeAddCommand

Previous iteration used some "magic code" that added clips automatically to the
timeline. This was functional but ultimately outside of the undo commands'
control meaning nodes could be infinitely added and abandoned. This makes the
add process part of the undo command which means it's all undoable as the user
would expect.

app/node/graph.h

@@ -50,31 +50,11 @@ public:
    */
   void AddNode(Node* node);
 
-  /**
-   * @brief Adds a node to this graph and all nodes connected to its inputs
-   *
-   * Adds the Node to the graph and runs through its inputs adding all of its dependencies (and all of their
-   * dependencies and so forth). The graph takes ownershi of all Nodes added through this process.
-   */
-  void AddNodeWithDependencies(Node* node);
-
   /**
    * @brief Removes a Node from the graph BUT doesn't destroy it. Ownership is passed to `new_parent`.
    */
   void TakeNode(Node* node, QObject* new_parent = nullptr);
 
-  /**
-   * @brief Removes a Node from the graph and its dependencies (ONLY if the dependencies are exclusive to this Node).
-   *
-   * Returns a list of all Nodes that were removed in this process (except the Node used as a parameter)
-   *
-   * Only dependencies that are exclusively dependencies of this Node are removed. If a dependency Node is also
-   * used as the dependency of another Node, it is not removed and not returned in the list.
-   *
-   * Ownership of all Nodes is passed to `new_parent`.
-   */
-  QList<Node*> TakeNodeWithItsDependencies(Node* node, QObject* new_parent = nullptr);
-
   /**
    * @brief Retrieve a complete list of the nodes belonging to this graph
    */