build: support building with eigen 5.0.0

[cho-m]

Existing find_package won't detect Eigen3 5.0.0. Upstream added support for range to help with this https://gitlab.com/libeigen/eigen/-/merge_requests/1989

However, the support is only available in 3.4.1+ so version 3.4.0 needs to use old approach.

Also, EIGEN3_INCLUDE_DIR was removed so instead just use Eigen3::Eigen target.

Eigen 3.4.0 has:

# Create imported target Eigen3::Eigen
add_library(Eigen3::Eigen INTERFACE IMPORTED)

set_target_properties(Eigen3::Eigen PROPERTIES
  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include/eigen3"
)

Eigen 5.0.0 has:

# Create imported target Eigen3::Eigen
add_library(Eigen3::Eigen INTERFACE IMPORTED)

set_target_properties(Eigen3::Eigen PROPERTIES
  INTERFACE_COMPILE_FEATURES "cxx_std_14"
  INTERFACE_INCLUDE_DIRECTORIES "${_IMPORT_PREFIX}/include/eigen3"
)