Fix: Geode v5 / GD 2.2081 compatibility migration

[Kosten47]

What this PR does

Migrates GDH from Geode SDK v4 to v5.0.0-beta.4 and adds compatibility
for Geometry Dash 2.2081.

Changes

Geode v5 API breaking changes

• Popup system rewrite: Popup<std::monostate> template removed in v5.
  All popup classes migrated to new Popup::init(width, height, bg) pattern
  (affects HacksLayer, RecorderLayer, LabelsCreateLayer, popupSystem)
• fmt library: fmt::localtime removed in fmt v12, replaced with
  geode::localtime
• Mod API: isOrWillBeEnabled() renamed to isLoaded()

GD 2.2081 binding changes

• GJBaseGameLayer::processCommands: signature changed from (float dt)
  to (float dt, bool isHalfTick, bool isLastTick)
• AudioEffectsLayer::m_notAudioScale: field removed, pulse control now
  only via FMODAudioEngine::m_pulse1
• GJGameLevel::m_k111: field removed in 2.2081 bindings
• CCEGLView::onGLFWKeyCallback: inlined in 2.2081, cannot be hooked.
  Replaced with CCKeyboardDispatcher::dispatchKeyboardMSG hook which
  properly converts VK codes to GLFW via KeyMappingUtils::GetGLFWFromWinAPI

Dependencies

• gd-imgui-cocos: hooks.cpp patched via CMake for 2.2081 compatibility
  (dispatchKeyboardMSG now takes an additional double time parameter).
  Patch applied automatically at build time from patches/imgui-cocos-hooks.cpp
• mod.json: updated GD version from 2.208 to 2.2081
• CMakeLists.txt: C++ standard updated from C++20 to C++23 (required by Geode v5)

Known limitations

• Right-click in ImGui menu not available (mouse callback inlined in 2.2081)
• Mobile recorder folder picker uses default writable path instead of
  manual folder selection

[TobyAdd]

Hello, the "main" branch is currently obsolete. It will remain for Geometry Dash 2.2074 and will no longer be maintained.

Currently, GDH is being rewritten, and the source code is published on the "new-5.1" branch, which includes extensive refactoring and code optimizations.

Also, you are using an incorrect method to update imgui-cocos. You need to change the commit hash in the CMakeLists.txt file instead of placing .cpp files in the build folder. Therefore, the pull request cannot be accepted.

[Kosten47]

Fixed, updated the commit hash in CMakeLists.txt. Sorry, first time contributing on github