3d text widget

[VictorKoenders]

This PR implements a basic of rendering text widgets in 3D space.

Fixes #5598

The following situation causes multiple textures:

commands.spawn(Text3dBundle {
    text: Text {
        sections: vec![
            TextSection::new(
                "normal ",
                TextStyle {
                    font: font_normal,
                    font_size: 24.0,
                    color: Color::BLACK,
                },
            ),
            TextSection::new(
                "bold",
                TextStyle {
                    font: font_bold,
                    font_size: 24.0,
                    color: Color::BLACK,
                },
            ),
        ],
        ..Default::default()
    },

    ..default()
});

There's a couple of ways to solve this:

• Add a material that supports multiple textures (I don't think bevy currently supports this)
  • Added ARRAY_TEXTURES support to shaders. #6842 can be used for this but is not merged yet
• Generating a child node for each unique info.glyphs[*].atlas_info.texture_atlas entry (would be a lot of node management)
• Make it so you can only generate a Text3dbundle with a single segment
• Document this behavior and fix it in the future, keeping the assert in place

For this PR I've decided to generate child node for each texture. Let me know if another solution is better.

---

Changelog

Breaking changes

• Renamed bevy_text::update_text2d_layout to bevy_text::update_layout::<Text2dBounds>
• bevy_text::extract_text2d_sprite is now limited to entities with a Text2dBounds component

Added

• Added bevy_text::Text3dBundle which allows rendering text in 3d space

[github-actions]

Welcome, new contributor!

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[github-actions]

Welcome, new contributor!

Please make sure you're read our [contributing guide](CONTRIBUTING.md) and we look forward to reviewing your Pull request shortly ✨

[github-actions]

Welcome, new contributor!

Please make sure you're read our [contributing guide](CONTRIBUTING.md) and we look forward to reviewing your Pull request shortly ✨

[VictorKoenders]

Rebased onto main

[github-actions]

Your PR increases Bevy Minimum Supported Rust Version. Please update the rust-version field in the root Cargo.toml file.

[mockersf]

Your PR increases Bevy Minimum Supported Rust Version. Please update the rust-version field in the root Cargo.toml file.

Sorry for the wrong message, the job checking for MSRV failed installing dependencies