Restructure shared modules and refactor CMake; update controller & flight code

[dridri]

This MR restructures the repository to consolidate common code, refactors the CMake build system, and brings in a number of new drivers, features and clean-ups across both the controller and flight targets.

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Key Changes

• Project structure & shared modules
  • Introduced a top-level libs/ directory for shared CMake scripts and common code
  • Renamed and reorganized Find*.cmake scripts (MP4V2, Nasm, QScintilla2, Shine, etc.)
  • Added a new submodule folder to centralize code used by both flight and controller targets
• Controller PC (controller_pc/)
  • Updated CMakeLists.txt to point at the new libs/ layout
  • Fixed broken references after tree reorg (main.cpp, Stream, UI files)
• Controller RC (controller_rc/)
  • Overhauled Config parsing (Config.cpp/.h) for more robust settings management
  • Refactored RPi-specific board code: • Optimized SPI and GPIO backends • Deprecated old Socket interface and replaced with cleaner client/server code
• Miscellaneous
  • Fixed ambiguous Lua-to-Matrix casts in the maths library
  • Small bug fixes and code style clean-ups throughout