File url can open path containing special chars (e.g., &?%)

o Clean up and simplification of the code
Adding cookie manager for downloading csv from websites which requires the client to handle cookies

o Add a helper class for spawning an http server for testing
Merge pull request #2077 from davidegrohmann/2.1-loadcsv-fixes-and-cleanups

Load CSV handles file urls with strange characteres (e.g., &?%) and http cookies