Improve code quality of pyChop and add unit tests

[Nick Draper]

Follow on from #7428.

The adopted code needs improvement and unit tests defined.

[Nick Draper]

(In #7428) This is just adding some python scripts, they are not added to the interfaces by this commit.

Passed, but follow on tickets created:

• #6891 Merge functionality with 'Garrets scripts' & add as interface
• #7554 Improve code quality & write unit tests

[Alex Buts]

fixing the existing code is not difficult. An simple interface for calculating resolution should be written. Then couple of specific classes would inherit from it and use existing code either to read data from file on disk or use current code which is wrong but can be deployed for the time being.

Doing all this should be no longer then a week (taking in consideration my reading on good practice for implementing python interfaces/inheritance and writing unit tests)

But there is Gurrets scripts which I know nothing about. In addition, it may requesting implementing chopper parameters database somewhere)

These are two unknowns which make this ticket unpredictable for me.

[Stuart Campbell]

This ticket has been transferred to github issue ​8399