Move ipython config within jupyterlab to docker image with more robust jupyterlab ssh tests

[costrouc]

Closes #1157

This PR serves a few purposes. All with the goal of making the docker images simpler (only has installed packages not configuration).

• reinstating the /etc/skel work that Dan added earlier to jupyterhub/qhub
• having the jupyter/ipython configuration managed by qhub (ties into the work that vini did in Adjust Idle culler settings and add internal culling #1133)
• removing the /etc/profile magic from the docker image which lead to weird ssh behavior with jupyterhub_ssh. This will fix the jupyterhub_ssh test and allow us to test the terminal behavior and user environment better.

[costrouc]

Need to test on a local cluster

[costrouc]

I've made the jupyterhub_ssh tests quite strict to ensure that the user environment it setup properly. Make take a few tries to get all the tests passing. I also changed the test username to be a complex example to test how jupyterlab handles this example-user+new1@example.com.

[viniciusdc]

Hi @costrouc I will add this to v0.4.x milestone, is it okay for you?

[costrouc]

This PR passes on the cloud tests as well https://github.com/Quansight/qhub-integration-test/runs/5452337353?check_suite_focus=true

[costrouc]

@viniciusdc this would be ready for review now that 0.4 has been released

[viniciusdc]

@viniciusdc this would be ready for review now that 0.4 has been released

I will review it thanks @costrouc, as I will deploy it to test the PS1 features and check the configmaps directly, I should finish it by next Monday.

[viniciusdc]

LGTM! I was able to check all configmaps were present and working. The skel configs were propagated and I was able to validate the pytests as well.

[costrouc]

I updated to the latest in main and if that passes I will merge.