cli/compose/loader: use gotest.tools/v3/golden

use the golden utility instead of self-crafting expected output,
this allows automaticaly updating the expected output.

This change does break this specific test on Windows due to platform-
specific paths. Other tests already have this issue on Windows, so
skipping the test for now.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Author: thaJeztah