EDGE image types are defined under a different name for RHEL-8.5,
specifically they don't contain the "rhel-" prefix any more. To ensure
backward compatibility, add image type aliases for all EDGE image types
with the "rhel-" prefix.
Image type aliases are used only when getting a specific imageType
instance by its name. When listing all available image types for an
architecture, only the current image type names are returned, without
any aliases. This prevents the image types from being exposed multiple
times under different names via Weldr API.
Extend the distro unit tests to test image type aliases.
Signed-off-by: Tomas Hozza <thozza@redhat.com>
3a2415d970