Entity Inspector

## Goal Description

Entity inspectors, such as [`bevy-inspector-egui`](https://github.com/jakobhellermann/bevy-inspector-egui), allow users to explore the state of a running Bevy `World` in a discoverable, interactive way. We should ship one with the engine, which can read and modify component values and resources, and comes with basic usability functions such as entity search.

Previously discussed in https://github.com/bevyengine/bevy/issues/15636.

## Goal Status

This is [Bevy Project Goal](https://bevy.org/learn/contribute/project-information/project-goals/) is currently **Approved (Active)**, as shown by its state on the [Project Goals Board](https://github.com/orgs/bevyengine/projects/23/views/1).

- **Staffing SMEs**: @alice-i-cecile
- **Working Group Link**: [Inspector General](https://discord.com/channels/691052431525675048/1430965607179878571)
- **Design Documents**: https://hackmd.io/tj99FqRITOGj1j2tuP2EAA
- **Previous discussion:** #15636

## Required work

- [ ] #1958