Port Sugar and core activities to Python 3

Sugar has 250+ repositories available on GitHub. Python 2.7.x, was officially discontinued on 1 January 2020. Sugar 0.116 runs on Python 2 or Python 3, core activities run on Python 3 and many other activities on Python 2, we need to make other activities compatible with Python 3 also before making a release. There are many activities which have been ported but contain errors and some still need a port. In this project, I would be making Sugar activities compatible with python 3 along with working on errors that prevent activities from being ported or used.