refactor(juju)!: use the jsh prefix for `juju show-*` commands (#10426)

BREAKING CHANGE: some aliases have been renamed to be consistent with the rest.
Mainly, aliases for `juju show-` commands are renamed to `jsh*`. This also means
that `jsh` and `jshc` have been renamed to `jssh` and `jsshc`. Have a look at the
README for the complete alias changes.