Migrate from Python2 to Python3

[justice-adams-apple]

Pull Request Description

Updated all Python scrips in the repository to support Python3 and dropped support for Python2. This included

• Fixing syntax errors throughout
• Using pythonic context managers to handle file management
• Using a proper Enum class for results handling
• Cleaning imports and updating shebang lines

I also took it upon myself to rename project_future.py -> project.py as we originally intended

Acceptance Criteria

Not applicable here

[justice-adams-apple]

Labelled as WIP for now because I need to do some manual testing quick while the CI build kicks off.

[justice-adams-apple]

@swift-ci test

[shahmishal]

LGTM! Thanks

[justice-adams-apple]

@shahmishal Will merge this today, just one question:

I saw some performance degradation when using python 3.7 to test my changes, in particular, things were just taking longer. After profiling the code I saw that the subprocess module was slower. This was fixed for macOS in 3.8+
https://docs.python.org/3.8/whatsnew/3.8.html#optimizations

And after updating to 3.9, I no longer saw an issue. The question is: Should we note on the readme that this repository is now targeting python 3.8+, just to be explicit for end-users? If so, I can update this branch quickly to include a change for the readme

[justice-adams-apple]

@swift-ci test

[shahmishal]

@shahmishal Will merge this today, just one question:

I saw some performance degradation when using python 3.7 to test my changes, in particular, things were just taking longer. After profiling the code I saw that the subprocess module was slower. This was fixed for macOS in 3.8+ https://docs.python.org/3.8/whatsnew/3.8.html#optimizations

And after updating to 3.9, I no longer saw an issue. The question is: Should we note on the readme that this repository is now targeting python 3.8+, just to be explicit for end-users? If so, I can update this branch quickly to include a change for the readme

Let's update the README to contain the info, it's ok to do this in new PR.