added user_scale scroll to drag targets

[jo372]

• updated to add a _on_gui_input event in the MicRecord scene. This is to detect user scroll as it's the only node available after you pass the main screen.

• added a SCALE_RATIO constant to increment / decrement when the user scrolls in or out

• added .scale to both the create_talking_atlas and create_normal_sprite this is to make sure the SCALE_RATIO is applied when the user clicks one of the three options HasMouth, Bounce and Blink as create_visual is called when either one of the options has been selected which dequeues the previous sprite and generates a new one.

[quellus]

Closes #5

[quellus]

@code807 and I approve! Thank you so much