Add example docs on how to simulate mouse pressed and releases through artifical events

**Your Godot version:**
v4.1.beta1.mono.official [828ec2c5d]

**Issue description:**
I am trying to understand how to simulate mouse button presses and releases without moving the mouse with the gamepad and keyboard.

The idea is that I would move the mouse, send a mouse button events and move it back but I can't get the control nodes to recognize the events and I don't know how to pass the correct position

**URL to the documentation page (if already existing):**
na