more clean up and moving functions from product assessment part 1 to functions script

major changes adding function to extract from raster, combine extracted data with assessmment and cleaning up

adding function to match specific set of station location from assembled stations of training and testing

gathering stations data for building time series, clean up of script for product assessment part1

product assessment part1 testing plot function for training residuals at at stations and fixing bugs, region 1

moving plot_stations_val_by_date to function script product assessment part1

testing plot for both training and testing and introducing a new function

adding function to plot residuals at location for product assessment part1

adding clipping functions for polygons and points in function script product assessment part1

examining stations extracted with histogram, assessment product part 1