Issue #3548254: Link requests made from the front-end to the API proxy

Closes #3548254

Testing instructions

• Compile the app and clear cache

  npm install
  npm run build -w app

• Add a key for your conductor account to the module settings page
• Go to a Canvas editor page and load the app
• Enter some keywords, check that you can evaluate them (must be more than 1 due to a Conductor API bug)
• Get a valid response/set of checkboxes for the Competitors tab (currently unstyled pending !66 (merged))