fix incorrectly named isIsoToIso, add IsoToIsIso

[maxsnew]

I had misnamed this function, oops

[felixwellen]

I'm a bit confused that there is IsoToIsIso but also isoToPath. I'm not sure if we ever came up for a good rule for the case when you have something which should start in lower case, but starts with a word that is usually in uppercase. I prefer using uppercase then, so I agree and just merge.