Definition of the Interface of ScriptRepository.h

re #6175
Implementation of ScriptRepositoryImpl

Implementation of the constructor, connect, install, download, info, listFiles, fileStatus methods.

re #6175
Introduction of the python script for ScriptRepository Web


It updates the web service repository.json file

re #6175
Definition of the unit test for ScriptRepository

PythonInterface: update the python interface that is exposed.
ScriptRepositoryImpl.h: set doDownloadFile as virtual, otherwise it is not override by the test mock.
scriptrepositoryparser : change the time format.
ScriptRepositoryImpl.cpp : solve some issues that appeared with the unit test.
ScriptRepositoryTestImpl: define many tests to ensure the functioning of the ScriptRepository.

re #6175
Merge branch 'feature/6175_script_repo' into develop