Fix windows MSVC build.

This CL improves the build experience with MSVC:
- It adds the build flag '/bigobj' otherwise the build of
  the unit test fails.
- It adds the flag '/wd4267' to suppress signed / unsigned int
  conversions (size_t to int).
- It removes the use of std::aligned_storage from FixedArray.
  This has been done from the Abseil Team and is in the
  absl::FixedArray. Those changes has been ported to ceres.
  This fixes the alignemnt for older MSVC versions due to a
  bug in the implementation of std::aligned_storage, and
  prevents the use of the macro '_ENABLE_EXTENDED_ALIGNED_STORAGE'
  for newer MSVC versions, which is problematic as it could affect
  user code.
- Fix of the fixed array unit test. Due to the use of std::tuple
  instead of absl::tuple in ceres::internal::FixedArray, the
  unit test needs to reflect that change as well.
- Replaces 'add_definitions' with 'add_compile_options' for
  compiler flags as suggested by the cmake documentation.

Change-Id: I63f08cd6c0a8db8c9931289b909b4deafd75b039