audit all commands to make sure none got changed or lost

[ianhi]

#63 got lost in the big changes in #58. That's fixed but it would be good to check that all keybindings were exactly preserved in that update

[fcollonval]

You may want to add test for this similar to https://github.com/jupyterlab/jupyterlab/pull/12116

To set integration test, you may look at https://github.com/jupyterlab/extension-cookiecutter-ts/pull/207