NIPET/CuVec speed tests

Testing https://github.com/NiftyPET/NIPET OSEM reconstruction before and after https://github.com/AMYPAD/CuVec integration.

1. Create two different Python3 environments
   • e.g. using conda create -n old python=3.9 and conda create -n new python=3.9
2. Configure paths in the Makefile
   • PATHTOOLS: Any directory in which to store extra binaries
   • HMUDIR: Directory containing proprietary Siemens hardware attenuation maps
   • DATA: Directory containing PET scan raw (listmode) data (e.g. from https://doi.org/10.5281/zenodo.3877529)
   • old.%: PY: Path to Python3 executable (for testing old version)
   • new.%: PY: Path to Python3 executable (for testing new version)
3. Setup
   • make old.setup
   • make new.setup
4. Run
   • make old.cprof
   • make new.cprof