Allow eslint-plugin-import to Resolve TypeScript Files

[DonIsaac]

What This PR Does

• Allow JS files to use CommonJS require()
• Add eslint-import-resolver-typescript so that eslint-plugin-import can resolve TypeScript imports
• Add typescript as a dev dependency
• Add a npm run typecheck script to run tsc on source code without emitting compiled output

[bmschmidt]

Is require() desirable? As someone who avoided javascript in the bad old days, I have an aversion.

[DonIsaac]

No, but it's needed in config files. I can modify the rules to only apply to those