Add IMPORTED_CONFIGURATIONS property for CMake targets

Some frameworks use the property in order to find libraries, e.g. like
https://github.com/ros/catkin/blob/noetic-devel/cmake/catkin_libraries.cmake#L150

In order to support these kind of usages, this commit adds the property
to all targets.

This should solve #14606 and #16688.

conan/tools/cmake/cmakedeps/templates/macros.py

@@ -88,6 +88,9 @@ def template(self):
                      message(DEBUG "Created target ${_LIB_NAME} ${library_type} IMPORTED")
                      set_target_properties(${_LIB_NAME} PROPERTIES IMPORTED_LOCATION${config_suffix} ${CONAN_FOUND_LIBRARY} IMPORTED_NO_SONAME ${no_soname_mode})
                    endif()
+                   string(REGEX REPLACE "^_" "" _LOWER_CASE_CONFIG ${config_suffix})
+                   string(TOUPPER ${_LOWER_CASE_CONFIG} _CONFIG)
+                   set_target_properties(${_LIB_NAME} PROPERTIES IMPORTED_CONFIGURATIONS ${_CONFIG})
                    list(APPEND _out_libraries_target ${_LIB_NAME})
                    message(VERBOSE "Conan: Found: ${CONAN_FOUND_LIBRARY}")
                else()