* feat(stacks): add the ability to migrate stacks to another endpoint
* feat(stack-details): do not redirect to alternate endpoint after migration
* fix(api): fix merge conflicts
* feat(stack-details): add a modal to confirm stack migration
* fix(api): add an authenticated access policy to the websocket endpoint
* refactor(api): centralize EndpointAccess validation
* feat(api): validate id query parameter for the /websocket/exec endpoint