Add bevy_dev_tools crate

[matiqo15]

Objective

• Resolves #11309

Solution

• Add bevy_dev_tools crate as a default feature.
• Add DevToolsPlugin and add it to an app if the bevy_dev_tools feature is enabled.

bevy_dev_tools is reserved by @alice-i-cecile, should we wait until it gets transferred to cart before merging?

[alice-i-cecile]

Added the A-Editor label: I'm going to group the dev-tools and editor PRs and issues together for triage until that proves to be a bad idea.

I'm going to wait on @cart's sign-off before merging this, but I think we're starting to get a clearer vision of what this crate might look like and can unblock editor-adjacent work now.

[mockersf]

should we wait until it gets transferred to cart before merging?

Not necessarily, but I think we should have something in those tools before merging. You could try moving https://github.com/bevyengine/bevy/blob/main/crates/bevy_app/src/ci_testing.rs

[alice-i-cecile]

I'm fine to move that into here as part of the initial PR. There's a number of other things I want to move and add, but this is a good uncontroversial first option.

[matiqo15]

Probably, we also want an option to enable only some tools

1st solution

We remove bevy_dev_tools from default features and lock every tool under a new feature - this is a simple solution but could grow out of control over time.

2nd solution

We create a resource to store information about dev tools (see DiagnosticsStore). There are a few reasons why I think this is better:

• Easier for users to add their own tools
• We could mark it as an editor/non-editor tool
• Show every enabled tool in the editor
• Possibly in the future, add/remove tool at runtime

I believe this could be done in a follow-up PR, to make it easier for review.

[alice-i-cecile]

Yep, IMO we add a few tools first, then start thinking about how to abstract them. I'd prefer to have it runtime configured too.

[cart]

Just left some thoughts in this thread: https://github.com/bevyengine/bevy/pull/11341/files#r1459692523

[BD103]

#12305 is a feature that fits the best in bevy_dev_tools. What needs to be done for this PR to be merged, to unblock the simplified backtraces one?

[alice-i-cecile]

https://github.com/bevyengine/bevy/pull/12305 is a feature that fits the best in bevy_dev_tools. What needs to be done for this PR to be merged, to unblock the simplified backtraces one?

So, IMO:

1. Resolve merge conflicts.
2. Bump to 0.14.0-dev.
3. Add a tool or two.
4. Get the final sign-off from @cart.

If there's no movement on this PR in the next week or so I'll adopt it and get it through :)

[pablo-lua]

If we want more tools here, maybe we can move Aabb gizmos here, or merge some tools that are not merged yet, like #11237, and move here. I think gizmos has a lot of tools hanging out there that can be moved.

[matiqo15]

I've rebased onto main