added ability to change default texture filter

[0x177]

resolves #762

[not-fl3]

LGTM, but maybe add it as a field to `conf::Conf as well?

[0x177]

conf::Conf doesn't seem as accessible as Context, so i do not see how i would access/change the default filter mode if it is stored in Conf

[not-fl3]

Something like this:

fn window_conf() -> Conf {
    Conf {
        default_texture_filter: Filter,
        ..Default::default()
    }
}

#[macroquad::main(window_conf)]
async fn main() {
    loop {
        clear_background(WHITE);
        next_frame().await
    }
}

[0x177]

this would require some minor changes to miniquad. i have made a pr for them

[0x177]

my recent commit has implemented it. here is an example of how the api may be used:

use macroquad::prelude::*;

fn window_conf() -> macroquad::conf::Conf {
    macroquad::conf::Conf {
	miniquad_conf: Conf {
            ..Default::default()
	},
	default_filter_mode: FilterMode::Nearest,
	update_on: None,
    }
}

#[macroquad::main(window_conf)]
async fn main() {
    let texture: Texture2D = load_texture("pixel.png").await.unwrap();
    
    loop {
        clear_background(LIGHTGRAY);
        draw_texture_ex(&texture, 0., 0., WHITE,DrawTextureParams {
	    dest_size: Some(Vec2::new(screen_width(),screen_height())),
	    ..Default::default()
	});
        next_frame().await
    }
}

[not-fl3]

Thanks for PR!