Have the openshell client role publish the installed gateway's name,
active TOML path, service scope, service user, and network, and add an
openshell_test_gateway role that loads that context, resolves the CLI,
restarts the gateway service, and collects its journal. A feature
suite can then change the gateway's active configuration for its own
run and restore it afterwards.
Select the candidate runtime images for packaged installs through a
qualification gateway.toml referenced by OPENSHELL_GATEWAY_CONFIG
instead of OPENSHELL_* variables in the service environment file, so
the gateway has a TOML file a suite can modify. Update the packaging
asset check to match.
Signed-off-by: Evan Lezar <elezar@nvidia.com>