fix(project-template): for cmake 3.16 (Ubuntu 20.04)

problem was introduced with commit "imported targets for set_csa"

cmake/set_control_system_adapter.cmake

@@ -29,18 +29,22 @@
 if(ADAPTER STREQUAL "OPCUA")
   message("Building against the OPC UA ControlSystemAdater")
   find_package(ChimeraTK-ControlSystemAdapter-OPCUAAdapter 03.00 REQUIRED)
+  set_target_properties(ChimeraTK::ChimeraTK-ControlSystemAdapter-OPCUAAdapter PROPERTIES IMPORTED_GLOBAL TRUE)
   add_library(ChimeraTK::SelectedAdapter ALIAS ChimeraTK::ChimeraTK-ControlSystemAdapter-OPCUAAdapter)
 elseif(ADAPTER STREQUAL "DOOCS")
   message("Building against the DOOCS ControlSystemAdater")
   find_package(ChimeraTK-ControlSystemAdapter-DoocsAdapter 01.08 REQUIRED)
+  set_target_properties(ChimeraTK::ChimeraTK-ControlSystemAdapter-DoocsAdapter PROPERTIES IMPORTED_GLOBAL TRUE)
   add_library(ChimeraTK::SelectedAdapter ALIAS ChimeraTK::ChimeraTK-ControlSystemAdapter-DoocsAdapter)
 elseif(ADAPTER STREQUAL "EPICSIOC")
   message("Building against the EPICS IOC ControlSystemAdater")
   find_package(ChimeraTK-ControlSystemAdapter-EPICS-IOC-Adapter 02.00 REQUIRED)
+  set_target_properties(ChimeraTK::ChimeraTK-ControlSystemAdapter-EPICS-IOC-Adapter PROPERTIES IMPORTED_GLOBAL TRUE)
   add_library(ChimeraTK::SelectedAdapter ALIAS ChimeraTK::ChimeraTK-ControlSystemAdapter-EPICS-IOC-Adapter)
 elseif(ADAPTER STREQUAL "EPICS7IOC")
   message("Building against the EPICS ver. 7.0 IOC ControlSystemAdater")
   find_package(ChimeraTK-ControlSystemAdapter-EPICS7-IOC-Adapter 02.00 REQUIRED)
+  set_target_properties(ChimeraTK::ChimeraTK-ControlSystemAdapter-EPICS7-IOC-Adapter PROPERTIES IMPORTED_GLOBAL TRUE)
   add_library(ChimeraTK::SelectedAdapter ALIAS ChimeraTK::ChimeraTK-ControlSystemAdapter-EPICS7-IOC-Adapter)
 else()
   message(FATAL_ERROR "Please select your ControlSystemAdapter to use by passing to the cmake command line:\n"