Bevy 9-Patch plugin

Implementation of 9-patch images in Bevy. Let you have a UI that scale only the right parts of your images.

See the examples for examples of what can be done.

Usage

Simple case

A simple builder based on Godot's NinePatchRect is available.

```rust let paneltexturehandle = assetserver .loadsync(&mut textures, "assets/glassPanel_corners.png") .unwrap();

commands
    .spawn(NodeComponents {
        style: Style {
            margin: Rect::all(Val::Auto),
            justify_content: JustifyContent::Center,
            align_items: AlignItems::Center,
            ..Default::default()
        },
        material: materials.add(Color::NONE.into()),

        ..Default::default()
    })
    .with_children(|global_parent| {
        bevy_ninepatch::NinePatchBuilder::by_margins(20., 20., 20., 20.)
            .apply(panel_texture_handle, &mut textures, &mut materials)
            .add(global_parent, 500., 300., |_, _| {});
    });

```

See simple.rs example for a complete example.

Usage as a plugin

A plugin and a component bundle are exposed, and can be used to add 9-Patch UI elements.

See plugin.rs example for a complete example.

Specify content to use

You can specify the content to be used inside the 9-Patch UI element. When creating a 9-Patch by specifying the margins, a content zone will be available by default for the center of the 9-Patch UI element.

See content.rs example for a complete example.

More flexible definition

It is possible to set any number of patches for an image, the only constraints is that all patches in a line must have the same height. Using this methods, different parts of the image can grow at different rates, and several content zones can be created.

See full.rs example for a complete example.