Sync cdp-frontend's npm commands for the app with cookiecutter-cdp-deployment's npm commands

cdp-frontend currently uses [snowpack](https://github.com/CouncilDataProject/cdp-frontend/blob/main/package.json#L14) as frontend build tool, while cookiecutter-cdp-deployment use [react-scripts](https://github.com/CouncilDataProject/cookiecutter-cdp-deployment/blob/main/%7B%7B%20cookiecutter.hosting_github_repo_name%20%7D%7D/web/package.json#L7).

The commands to start the app locally and build the app should be the same between the two repos.

Also, add CI to build the app in the [PR workflow](https://github.com/CouncilDataProject/cdp-frontend/blob/main/.github/workflows/test-lint-and-build.yml).