Modernize cmake project files

Fix install target

Update cmake-format config file

Format all cmake files.

Update CPM.cmake version.

Use FILE_SET HEADER to verify and install the header files.

Prevent build problems caused by CPM_USE_LOCAL_PACKAGES

Prevent problems with doctest if local found

cmake/Config.cmake.in

@@ -0,0 +1,10 @@
+include(CMakeFindDependencyMacro)
+
+string(REGEX MATCHALL "[^;]+" SEPARATE_DEPENDENCIES "@PROJECT_DEPENDENCIES@")
+
+foreach(dependency ${SEPARATE_DEPENDENCIES})
+  string(REPLACE " " ";" args "${dependency}")
+  find_dependency(${args})
+endforeach()
+
+include("${CMAKE_CURRENT_LIST_DIR}/@PROJECT_NAME@Targets.cmake")