Add granular CMake targets with BUILD_SHARED_LIBS support

[afrind]

Summary:
This adds granular CMake targets to fizz, similar to folly's granular targets.
Each fizz library (e.g., fizz_crypto_hkdf, fizz_protocol_certificate) can now
be linked individually, reducing binary sizes for applications that only need
specific functionality.

Key changes:

• Added FizzFunctions.cmake with fizz_add_library() function that:

  • Creates OBJECT libraries (compiled once, used for both granular and monolithic)
  • Creates STATIC libraries for individual linking (static builds)
  • Creates INTERFACE libraries linking to monolithic fizz (shared builds)
  • Handles deferred dependency resolution for internal fizz deps
  • Links Folly::folly and optional deps (OQS, aegis) in shared builds

• Added granular CMakeLists.txt for each subdirectory, generated from BUCK
  files using generate_cmake.py. Manually maintained for:

  • backend/ (conditional libaegis/liboqs logic)
  • compression/ (conditional brotli logic)

• Added generate_cmake.py to auto-generate CMakeLists.txt from BUCK files

• Added lint_cmake_sync.py for arc lint integration

Build behavior:

• BUILD_SHARED_LIBS=OFF: Creates individual .a files + monolithic libfizz.a
• BUILD_SHARED_LIBS=ON: Creates INTERFACE targets linking to libfizz.so

Differential Revision: D91009035

[meta-codesync]

@afrind has exported this pull request. If you are a Meta employee, you can view the originating Diff in D91009035.