Fix CMake Install: Find*.cmake Modules

Install the CMake modules in `cmake/` into our install
prefix. If we build with external dependencies for LZ4 and ZLIB_NG,
will need those Modules to populate our CMake import targets in
`Blosc2Config.cmake` during the `find_dependency` calls (which
are just wrappers for `find_package`).

Blosc2Config.cmake.in

@@ -9,7 +9,7 @@ if(POLICY CMP0074)
 endif()
 
 # locate the installed FindABC.cmake modules
-list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake")
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/Modules")
 
 # this section stores which configuration options were set
 set(HAVE_THREADS @Threads_FOUND@)

CMakeLists.txt

@@ -520,6 +520,12 @@ if(BLOSC_INSTALL)
         DESTINATION ${Blosc2_INSTALL_CMAKEDIR}
     )
 
+    # CMake Find*.cmake files used in Blosc2Config.cmake
+    install(
+        DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/cmake/
+        DESTINATION ${Blosc2_INSTALL_CMAKEDIR}/Modules
+    )
+
     # pkg-config .pc file
     configure_file(
          "${CMAKE_CURRENT_SOURCE_DIR}/blosc2.pc.in"