## What does this PR do?
Improves `xtool dev generate-xcode-project`. Instead of constructing an
XcodeGen project, we directly construct an xcodeproj (with the new
xcproj format) using
[apple/xcode-project-format](https://github.com/apple/xcode-project-format).
For now, we still rely on
[Tuist/XcodeProj](https://github.com/tuist/XcodeProj) to translate it
back into a pbxproj for maximal compatibility, but this is treated as an
implementation detail.
Also adds support for resources and icons in the generated Xcode project
## How was it tested?
- [x] Generated a simple project, opened it, and ran the app
## AI tool usage
How much of this PR was AI-assisted? (check one)
- [ ] **0** - No AI was used to write code
- [x] **1** - I was assisted by AI. I reviewed the finished result.
- [ ] **2** - I set the AI going and left it to it; nobody has read the
result - no review, or AI review only
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<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* Added support for creating and saving Xcode projects and workspaces in
`.pbxproj` and `.xcproj` formats.
* Added tools for opening, converting, and writing project and workspace
files, including workspace contents.
* Project generation can target a specified directory, and the command
reports where the project was created.
* Project generation is available on non-macOS platforms.
* Generated projects include product settings and references for
packages, resources, icons, and app extensions.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Kabir Oberai