Add slider menu item, configuring on-screen controls size

[Vankata453]

Adds the ItemSlider menu item. It allows selecting an integer value between a minimum and a maximum value. It can be used with the left mouse button, left/right arrow keys or scroll wheel. The slider step (interval between values when using the arrow keys or scroll wheel) is configurable from "Options" -> "Advanced".

The sound volume, music volume and flash intensity options now utilize a slider. The on-screen controls scale option was added back in "Options" -> "Controls" and utilizes a slider as well.

https://github.com/user-attachments/assets/63888af9-24da-43a2-a44c-52e24aa057f7

Additionally:

• The on-screen controls toggle has also been re-added in "Options" -> "Controls".
• The on-screen controls configuration values were changed to allow for broader scale customization.

Closes #3010. Closes #3033.