This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release.
The examples are all ported over and operational with a few exceptions:
* I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure.
* Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example.
* Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority.
# Objective
Port bevy_ui to pipelined-rendering (see #2535 )
## Solution
I did some changes during the port:
- [X] separate color from the texture asset (as suggested [here](https://discord.com/channels/691052431525675048/743663924229963868/874353914525413406))
- [X] ~give the vertex shader a per-instance buffer instead of per-vertex buffer~ (incompatible with batching)
Remaining features to implement to reach parity with the old renderer:
- [x] textures
- [X] TextBundle
I'd also like to add these features, but they need some design discussion:
- [x] batching
- [ ] separate opaque and transparent phases
- [ ] multiple windows
- [ ] texture atlases
- [ ] (maybe) clipping
