analysis functions for postplot added

post plot:
- commented sourcecode removed

prototype:
- import of data_logger ip
- get sensor values modified for new data logger
- names of data frame columns changed
- modfications with sensor channel import from json file ext_sens_param
- post plot function modfied for calling modified module for post plot

function for determing PK2PK values of phase and magnitude
function for changing annotation test in first subplot

modify module for measurement plot for external sensors
add module for post
modifiy prototype for external sensors and error handling of communcation errors of VNA
add regresson to post plot with basich control elements