Show a selected Bone Gizmo when Clicking on it keyframe

### Tested versions

Godot v4.3.stable

### System information

Ubuntu 24.04 LTS 24.04 - Wayland - GLES3 (Compatibility) - Mesa Intel(R) HD Graphics 2000 (SNB GT1) - Intel(R) Core(TM) i5-2400 CPU @ 3.10GHz (4 Threads)

### Issue description

[Screencast from 2024-08-23 16-28-05.webm](https://github.com/user-attachments/assets/736deec5-da14-4424-bfb3-d5095085ecc9)

Animating inside godot is pretty annoying after the Skeleton3D lose focus:

1 - it disables edit mode
2 - Clicking on a specific keyframe belong to a Bone rotation ... will do nothing (even if the Skeleton3d is on edit mode)

### Steps to reproduce


clicking on a keyframe should show a Gizmo for the selected bone
currently, it does nothing

### Minimal reproduction project (MRP)

N/A

Start by reproducing the behavior in Godot v4.3 with a Skeleton3D, animation keyframes, and edit mode, using the attached screencast and reproduction steps. Trace the editor path handling clicks on bone-rotation keyframes and compare it with selection behavior when the Skeleton3D retains focus. Done means clicking a relevant keyframe selects the bone and displays its gizmo, including after focus is lost.

Written by the indexing model from the issue text.