macOS Metal + AppKit app

[louwers]

• Remove unused macOS scripts.
• Add Bazel targets for macOS (main toolkit, AppKit app, GLFW app, cache tool, render tool)
• Update CI to build macOS (no tests yet).
• Switch to libuv instead of CFRunLoop on macOS.
• Modify .clang-format to make pre-commit happy. I can maybe apply Objective-C formatting to the entire codebase in a later PR.
• Updated Bazel.
• Improved config handling.
  • The config is shared between macOS and iOS
  • Location: platform/darwin/bazel/config.bzl
  • By default, the example config is used. This is useful for including this repo in another Bazel workspace.

I would like to get this merged because it's already getting quite a big change. To be addressed later:

• TODO: the AppKit app probably had it's own run loop, because it's missing one now. We need to either:
  • Get the CFRunLoop working (again) under macOS, or:
  • Kick off the libuv based run loop on macOS AppKit
• TODO: GLFW Bazel build for other platforms?
• TODO:: re-use platform/glfw/metal_backend.mm for other platforms (Qt, Node.js?) move to platform/darwin

[github-actions]

Bloaty Results 🐋

Compared to main

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  [ = ]       0  +0.0%     +16    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results/pr-2205-compared-to-main.txt

Compared to d387090 (legacy)

    FILE SIZE        VM SIZE    
 --------------  -------------- 
   +20% +23.1Mi  +406% +24.3Mi    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results/pr-2205-compared-to-legacy.txt

[github-actions]

Benchmark Results ⚡

Benchmark                                                     Time             CPU      Time Old      Time New       CPU Old       CPU New
------------------------------------------------------------------------------------------------------------------------------------------
OVERALL_GEOMEAN                                            -0.0019         -0.0014             0             0             0             0

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/benchmark-results/pr-2205-compared-to-main.txt

[github-actions]

Bloaty Results (iOS) 🐋

Compared to main

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  [ = ]       0  [ = ]       0    TOTAL

Full report: https://maplibre-native.s3.eu-central-1.amazonaws.com/bloaty-results-ios/pr-2205-compared-to-main.txt