cmake BTF examples

AMICI-dev/AMICI ThirdParty/SuiteSparse/CMakeLists.txt :127 

find_package ( BTF 2.3.2 REQUIRED )

DrTimothyAldenDavis/SuiteSparse CMakeLists.txt :128 

find_package ( BTF 2.3.3 REQUIRED )

jlblancoc/suitesparse-metis-for-windows SuiteSparse/Example/CMakeLists.txt :92 

find_package ( BTF 2.3.1 REQUIRED )