WIP: add a new dependency Garfield.

cmake/CEPCSWDependencies.cmake

@@ -5,6 +5,7 @@ Find all the dependencies here, so in each package user don't need to find the p
 - CLHEP
 - DD4hep
 - EDM4hep
+- Garfiel++/Garfieldpp
 - Gaudi
 - Geant4
 - GEAR
@@ -21,6 +22,7 @@ Find all the dependencies here, so in each package user don't need to find the p
 find_package(CLHEP REQUIRED;CONFIG)
 find_package(DD4hep COMPONENTS DDCore DDG4 DDParsers DDRec REQUIRED)
 find_package(EDM4HEP REQUIRED)
+find_package(Garfield REQUIRED)
 find_package(Geant4 REQUIRED ui_all vis_all)
 find_package(GEAR REQUIRED)
 find_package(GSL REQUIRED)