New file service, multiple file upload feature and minor fixes

1) Renamed FileTransporter to FileProcessor interface due to new FileUtility service adding.
2) Added file utility + service for processing common file system actions like create / delete / exists.
3) Performed some classes renaming to make more logical sense.
4) Added new file utility APIs into client.
5) Modified tests to allow remote file system control.
6) Added integration test for all common functionality instead of raw sikulix test.
7) Fixed README.md files according to added changes.
8) Modified screenshots to use english OS version.
9) Minor bug fixes.
10) Added remote IP into client logs.
11) Execution logger was encapsulated to CommandLineUtility.
12) Added multiple file upload feature.