Return extras with at least one installed dependency.
Deliberately looser than get_extras_status, which requires every declared
package to be present. Callers here rebuild install commands, so a partially
installed extra must still be preserved across an upgrade; dropping it would
silently uninstall what the user asked for. Do not harmonize the two.
Name of the installed distribution to inspect.
Raise when the distribution metadata cannot be read or parsed reliably.
