Feat: Implemented keyboard shortcut Alt to perform a centered resize

[LeonardoAlvess]

While holding the Alt key and resizing an instance, both sides are resized. This was achieved by doubling the scaling factor and updating the new X and Y coordinates without using a fixedPoint. Closes issue #6160

[AlexandreSi]

Thanks for the suggestion! It works like a charm for sprites and tiled sprites, but with 3D models, there are some strange behaviors (it depends on the model default X rotation). Have you tried with other object types ? (Panel sprite, tilemaps for instance)

[LeonardoAlvess]

Hi! Thanks for the review. We just reviewed the interaction with other object types and there is in fact a buggy interaction, we will get right on it and get a solution as soon as possible!

[LeonardoAlvess]

Could you clarify the what you mean by "depends on the default X rotation?".

[AlexandreSi]

Here is a video to reproduce the particular issue I saw:

https://github.com/4ian/GDevelop/assets/32449369/bcf4b284-d3db-4f13-b427-961b96457b45

Depending on the Default X Rotation, the point that does not move is never the same 😅

[DavidMLPalma]

Hi @AlexandreSi, Thanks for the explanation! We will try to get on it as soon as possible.