Fix #867 ESLint Config

[Rodhlann]

Reworks eslint config to remove existing errors, and eslint ignore blocks

PR fixes #867

Changes

• rework eslint config
• fix any existing errors
• remove eslint ignore blocks and resolve related issues
• added TODOs for unused variables to confirm if they should be kept

Notes

• My editor is configured to auto-fix style issues on save, let me know if that's obnoxious (there's a lot of spacing / formatting updates in here because of that)
• When running mvn clean install eslint errors are still being reported, it seems that when react-app-rewired is being temporarily installed during the install it's using its own eslint config that doesn't match what we have here. I am unfamiliar with that package and am not sure how to overwrite it to use our own, but am open to any ideas there!

[TanyaStere42]

Everything looks good to me, want a double check from @erinz2020 about package-lock.json but should be good to merge after that

[erinz2020]

package-lock.json looks good to me