[RTADPA BW tests] Cleanup copying of HLT2 BW test output -> eos & allow overwrite

FYI @lugrazet

Goes with lhcb-datapkg/PRConfig!362 (merged)

• Cleanup logging after !267 (merged)
• Only save output to current_hlt2_output/ directory. I was previously interested if you could save to a new directory, which clearly you can, and now I think we should just put everything we need for the BW tests in this directory to be neat.
• Add -f flag to the eos copying so it can overwrite