Rewrite the frontend to remove job id from requests

[definitelynobody]

Rewrite and test the frontend script so that the job id is not passed to the /out or /err endpoints. Instead store the job id locally when the job is created and compare it with the job id that is returned from those endpoints. If the job has changed, clear the console and store the new job id.

.route("/out/:id", post(read_stdout))

should be

.route("/out", post(read_stdout))