test: lxc image list --all-projects

This commit adds tests for listing images across all projects.

Signed-off-by: Kadin Sayani <kadin.sayani@canonical.com>

test/suites/projects.sh

@@ -396,6 +396,9 @@ test_projects_images() {
   lxc project switch default
   ! lxc image list | grep -q "${fingerprint}" || false
 
+  # The imported image is visible in the default project when the all-projects flag is set.
+  lxc image list --all-projects | grep -q "${fingerprint}"
+
   # Switch back to the project and clean it up.
   lxc project switch foo
   lxc image delete "${fingerprint}"
@@ -419,6 +422,9 @@ test_projects_images() {
   # The image alias from the default project is not visible here
   ! lxc image list | grep -q testimage || false
 
+  # The image alias from the default project is visible when the all-projects flag is set.
+  lxc image list --all-projects | grep -q testimage
+
   # Rename the image alias in the project using the same it has in the default
   # one.
   lxc image alias rename foo-image testimage