ch-run: don’t mount user home by default

[j-ogas]

Remove user home directory from default binds. Make --no-home default behavior and replace it with, --home, a convenience argument that binds the user home directory.

Unlike the other default binds, the user's home directory:

1. isn't required for functionality or hardware visibility; rather, it is primarily included for convenience, e.g., dotfiles for interactive sessions; and
2. can cause obscure, unintended runtime behavior when dotfiles manipulate environment variables like PATH, PYTHONHOME, MPI_HOME, etc.

Default binds should not have unintended run time consequences.

[qwofford]

This caught my attention. After reading the issue description, I agree with the logic. I vote for a big obvious announcement on version release! In bold! With colors! @azukaitis