CMake: Rewrite FindMKL.cmake #16408

Job	Run time
Build without MPI	6m 12s
Build extra components with GNU toolchain	16m 56s
Build without ELPA	7m 34s
Build with CUDA support	13m 36s
Build without LCAO and MPI	4m 10s
Build extra components with Intel toolchain	14m 46s
Build with Intel toolchain	7m 54s
Build without LCAO	5m 18s
Build with GNU toolchain	8m 8s
	1h 24m 34s

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