Fix codebox highlighting after switching files

[damianhxy]

Description

Moved #highlightLongLines event listener into attachEvents function.

Motivation and Context

Currently, the event listener for the "highlight lines longer than 80 characters" checkbox is only attached once on page load.

However, when switching files, the elements of the codebox is replaced, meaning that the listener no longer works.

This PR attaches the event listener inside the attachEvents function instead, which is called on

• page load
• switching files (cached)
• switching files (uncached)

How Has This Been Tested?

• Make a submission with a file containing > 80 characters (for example, submit to hello and the first line of the autograder output suffices)
• Load autograder output directly, check box functionality (page load)
• Load another file directly, check box functionality (switching files uncached)
• Load autograder output directly, switch away and switch back, check box functionality (switching files cached)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have run rubocop for style check. If you haven't, run overcommit --install && overcommit --sign to use pre-commit hook for linting

[20wildmanj]

Change looks good to me, and verified that highlighting stays active after switching. I was unable to reproduce the original case of highlighting failing however, if possible could I get a more specific flow to break the highlighting?

[damianhxy]

Screen.Recording.2022-11-23.at.11.56.49.mov

[20wildmanj]

Ah I see, was able to reproduce. All good to merge in