Upgrade to Bevy 0.14.0-rc.* & upgrade egui-gizmo dependency

[zhaop]

This PR allows bevy_editor_pls to be used with the newest Bevy 0.14 rc (currently at least rc.3), and is based on top of #106 by @ActuallyHappening .

Before anything happens to this, we should probably first:

• Get Update gizmo crate to transform_gizmo_bevy to update egui version #106 merged & rebase this PR on top
• Wait until Bevy 0.14.0 is officially released, change the dependencies to point to that, and make sure this still works then

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Concretely, this implements the following migration steps:

• Refactor App and SubApp internals for better separation bevyengine/bevy#9202 : Use app.world_mut() or .world() instead of .world
• #12502 Remove limit on RenderLayers. bevyengine/bevy#13317 : Clone RenderLayers when necessary & change underlying type to usize
• Refactor App and SubApp internals for better separation bevyengine/bevy#9202 : Match app.get_sub_app as Option instead of Result
• Migrate from LegacyColor to bevy_color::Color bevyengine/bevy#12163 : Use Color::srgb* instead of Color::rgb*
• Fix TypeRegistry use in dynamic scene bevyengine/bevy#12715 : Change to DynamicScene::serialize(&TypeRegistry)

[zhaop]

Or maybe this PR can be more self-contained and doesn't have to include the egui-gizmo change 🤔

[alphastrata]

bevy 14 is out now so you can probs update those git deps to be actual versioned deps

[zhaop]

Oops, just wanted to rename the branch to bevy-0.14 but that closed the PR. Probably a good idea anyway, #110 is the PR targeting the new official release :)

@alphastrata The Bevy dependency has been upgraded to the official version in #110, but looks like some of the dependencies still need to get their upgrades pushed to crates.