Move close_on_esc to bevy_dev_tools

[BD103]

Objective

• As @james7132 said on Discord, the close_on_esc system is forcing bevy_window to depend on bevy_input.
• close_on_esc is not likely to be used in production, so it arguably does not have a place in bevy_window.

Solution

• As suggested by @afonsolage, move close_on_esc into bevy_dev_tools.
  • Add an example to the documentation too.
• Remove bevy_window's dependency on bevy_input.
  • Add bevy_reflect's smol_str feature to bevy_window because it was implicitly depended upon with bevy_input before it was removed.
• Remove any usage of close_on_esc from the examples.
  • bevy_dev_tools is not enabled by default. I personally find it frustrating to run examples with additional features, so I opted to remove it entirely.
  • This is up for discussion if you have an alternate solution.

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Changelog

• Moved bevy_window::close_on_esc to bevy_dev_tools::close_on_esc.
• Removed usage of bevy_dev_tools::close_on_esc from all examples.

Migration Guide

bevy_window::close_on_esc has been moved to bevy_dev_tools::close_on_esc. You will first need to enable bevy_dev_tools as a feature in your Cargo.toml:

[dependencies]
bevy = { version = "0.14", features = ["bevy_dev_tools"] }

Finally, modify any imports to use bevy_dev_tools instead:

// Old:
// use bevy::window::close_on_esc;

// New:
use bevy::dev_tools::close_on_esc;

App::new()
    .add_systems(Update, close_on_esc)
    // ...
    .run();