[mr/1231] commands: fix `@step(u'"{pattern}" is visible with tab after "{command}"')`

We also need to set completion-query-items 0 to prevent the

Display all 283 possibilities? (y or n)

message.

While at it, don't override files in the user's home directory. In particular, don't leave the garbage there behind. Use instead the bind builtin.

See-also: NetworkManager!1231 (comment 1398101)