Fix XDG_CONFIG_DIRS parsing
Factor instance table printing in its own method
Allow selecting instances directly from the command line

This commit adds a new --match (or -m) command line option that allows
passing a fuzzy string to match against all the columns of an instance
in the instance table. The table will be filtered to show only the rows
of the matching instances. If only a single instance matches, the prompt
is skipped and that instance is selected automatically.
Mention the instance ID when connecting to an instance