Remove lint errors for event handler functions that don't use the event argument

[erikquinn]

Some event handler functions currently don't use the event itself for anything. Therefore, eslint is showing errors because the argument should either be used or not taken. But in this particular case, it is wise to capture the event just so we know it is available, even though we occasionally may not need it.

Please add individual eslint comments for each of these instances such that cause eslint to ignore them so they are considered legal.

[n8rzz]

Please add individual eslint comments for each of these instances such that cause eslint to ignore them so they are considered legal.

Don't do that. We can use this issue to update our .eslint rules to allow for this.

[erikquinn]

Here's what we came up with on slack:

no-unused-vars: ["error", { "argsIgnorePattern": "event" }]

See the no-unused-vars rule for further:
https://eslint.org/docs/rules/no-unused-vars#argsignorepattern

This should globally suppress the errors for unused arguments called event.

[n8rzz]

will be covered under #744 (#746)