Consider builder pattern for adding images

[torsteingrindvik]

What problem does this solve or what need does it fill?

We have lots of code such as this:

bevy/examples/ui/viewport_node.rs

Line 49 in 775fae5

let image = Image {

Search for TextureDimension in the examples folder and there are many hits.

It typically looks like so:

    let size = Extent3d {
        width: window_size.x,
        height: window_size.y,
        ..default()
    };
    let format = TextureFormat::Bgra8UnormSrgb;
    let image = Image {
        data: Some(vec![0; size.volume() * format.pixel_size()]),
        texture_descriptor: TextureDescriptor {
            label: None,
            size,
            dimension: TextureDimension::D2,
            format,
            mip_level_count: 1,
            sample_count: 1,
            usage: TextureUsages::TEXTURE_BINDING
                | TextureUsages::COPY_DST
                | TextureUsages::RENDER_ATTACHMENT,
            view_formats: &[],
        },
        ..default()
    };
    let image_handle = images.add(image);

It's quite verbose and is (arguably) needlessly close to the wgpu innards.

What solution would you like?

We could expose a builder pattern which would look along the lines of:

let image = ImageBuilder::new_2d(vec2(window_size.x, window_size.y))
    .data(vec![0; size.volume() * format.pixel_size()])
    .usage(TextureUsages::TEXTURE_BINDING
        | TextureUsages::COPY_DST    
        | TextureUsages::RENDER_ATTACHMENT);

// mip level, sample count, texture format, view formats have sane defaults
// and have builder methods for users who need them

let image_handle = images.add(image.build());

and similar for 3d (maybe 1d?).

Some bikeshedding opportunities:

• usage(flags) vs usage_texture_binding() + usage_copy_destination() + ...
• new_2d(size) could zero by default, making .data() unnecessary unless there was actual non-zero data to provide

What alternative(s) have you considered?

Just keeping things as-is.

Additional context

Some discord context: https://discordapp.com/channels/691052431525675048/692572690833473578/1369263245608620082

[chompaa]

Related: #17209.