Live deployment of PR's

Changes to the webapp usually result in some visual changes that we want to inspect and provide feedback on.

Right now, we do this by capturing snapshots on the changes from our local development environments. Apart from being a bit risky (maybe the snapshot was taken from some stale code..?), it also doesn't allow reviewers to properly evaluate the changes.

We could leverage [GitHub Deployment](https://docs.github.com/en/rest/guides/delivering-deployments) and deploy a live environment for every PR, this deployment will post a URL in the status check that can be navigated to and inspected.

To reduce costs or un-necessary deployments, we could make it so deployments only happen for PR's labeled with some label, added by the author.