Move the find_package(SuiteSparse) from istl to common

Summary

Move the find_package call into DuneCommonMacros.cmake, since the defines #HAVE_SUITESPARSE_XYZ are in dune-common.

See associated MR in dune-istl!538 (merged).

cmake/modules/DuneCommonMacros.cmake

@@ -37,6 +37,10 @@ include(AddMETISFlags)
 find_package(ParMETIS 4.0)
 include(AddParMETISFlags)
 
+# find libraries for sparse matrix factorizations
+find_package(SuiteSparse OPTIONAL_COMPONENTS CHOLMOD LDL SPQR UMFPACK)
+include(AddSuiteSparseFlags)
+
 # try to find the Vc library
 set(MINIMUM_VC_VERSION)
 if((CMAKE_CXX_COMPILER_ID STREQUAL Clang) AND