Improve safety of strings used as paths

[hassila]

So it works on e.g. Windows etc, some input here:

https://rdrr.io/cran/fs/src/R/sanitize.R
https://forums.swift.org/t/unsafe-characters-in-file-names-redux/65764

Should check swift-foundation if anything exists already and consider an extension to either system or swift-foundation or string for this.

cleanupStringForShellSafety should be replace with this new function.

[hassila]

Also for absolute threshold checks we don't seem to clean up the string properly (so benchmarks with spaces in the name fails - workaround is to use camel case).