Read transfer function measurement from txt file

This will be used for the roaming lines analysis (or it may be). The text file will already be corrected for time dependence so we don't need to take care of that and the txt files are at high frequency, so we don't need to worry about effects from the loop suppression. Essentially the measurement is C

Example of analysis results (however there may be something slightly wrong with the coherence values as inputs in the test ASCII data file--this is being followed up by Dripta):