add texture_scale_mode

[jagprog5]

PR got deleted once the fork was detached. Recreating it here.

Adds texture scale mode binding

[jagprog5]

I didn't include the following test, as it requires creating a texture creator and doubt this would work with the CI:

use sdl3::{pixels::PixelFormat, render::{ScaleMode, SurfaceCanvas}, surface::Surface};
use sdl3_sys::pixels::SDL_PIXELFORMAT_RGB24;

extern crate sdl3;

#[test]
fn test_scale_mode() {
    let sdl_context = sdl3::init().unwrap();
    let sdl_video_subsystem = sdl_context.video().unwrap();
    let window = sdl_video_subsystem
    .window(
        "tester",
        100,
        100,
    )
    .build()
    .unwrap();

    let canvas = window.into_canvas();
    let texture_creator = canvas.texture_creator();
    let surface = Surface::new(1, 1, PixelFormat::try_from(SDL_PIXELFORMAT_RGB24).unwrap()).unwrap();
    let mut texture = texture_creator.create_texture_from_surface(surface).unwrap();

    // checking the default scale mode
    assert_eq!(texture.scale_mode(), ScaleMode::Linear);
    // check set get
    texture.set_scale_mode(ScaleMode::Nearest);
    assert_eq!(texture.scale_mode(), ScaleMode::Nearest);
}