We are concerned that now we are using webpack that ES6 syntax make leak into production, given we are working with Node modules.

Acceptance criteria

• The resources/dist folder should be linted to check that it is using ES5 compatible syntax
• If it's not possible to use an eslint config, we should add a transpiler to ensure this.

Sign off steps

• Revisit the discussion in T202753 and create a new task if we feel like the concerns raised there have not been addressed.