Make the requiredProjectId work with the online editor

[paulkaplan]

Resolves

What Github issue does this resolve (please include link)?

• Resolves Handle required project for a tutorial in a better way #4072

Proposed Changes

Describe what this Pull Request does

If you aren't on the tutorial project, open it in a new tab in a way that'll work in production

[ericrosenbaum]

hmm, travis is failing in a way that may be legit, on "Load a project by ID directly through url"

[benjiwheeler]

LMK if you want me to take a look at the overlap with project-state

[paulkaplan]

@ericrosenbaum that is suspicious, although it is running locally for me, so I'm going to rerun it. The code changes were only in the tips library, so although project loading is involved, none of that code should be being touched.

[paulkaplan]

@ericrosenbaum confirmed that was a problem with project server, not us.

I also implemented a confirm to prevent you from leaving a project with unsaved changes. It isn't great, but I figure anything is better than losing work.

[paulkaplan]

@chrisgarrity this can be reviewed now. It keeps the window opening behavior, but changes it to open the project at /projects/<project id>?tutorial=<tutorial id>. Note that this wont work in staging due to missing project, but works in prod

[chrisgarrity]

One little change: the new URL should open the editor.

[chrisgarrity]

Looks good. I uploaded a copy of the project to my local copy. Replacing the project id with the one on my local one worked great.