fix(BA-67): service list CLI command always print image as (null)

[jopemachine]

Fixes #3014 (BA-67).

Test

Tested manually.

./backend.ai service list
Endpoint Id                           Name                    Image                                             Desired Session Count  Routings                     Session Owner                         Open To Public
------------------------------------  ----------------------  ----------------------------------------------  -----------------------  ---------------------------  ------------------------------------  ----------------
8e2175fb-1a07-4bb8-8a8b-af0d0419e111  bai-serve-autumn79      cr.backend.ai/multiarch/python:3.9-ubuntu20.04                        2  PROVISIONING 1, UNHEALTHY 1  f38dea23-50fa-42a0-b5ae-338f5f4693f4  False
f72c3527-7996-413f-bd90-f5b037dfbf92  bai-serve-manuelmorris  cr.backend.ai/multiarch/python:3.9-ubuntu20.04                        2  UNHEALTHY 2                  f38dea23-50fa-42a0-b5ae-338f5f4693f4  False
62174018-06af-4d25-9acc-2d75aec28d58  bai-serve-steven63      cr.backend.ai/multiarch/python:3.9-ubuntu20.04                        2  UNHEALTHY 2                  f38dea23-50fa-42a0-b5ae-338f5f4693f4  False

Checklist: (if applicable)

• Milestone metadata specifying the target backport version
• Test case(s) to:
  • Demonstrate the difference of before/after

[jopemachine]

Warning

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Learn more

• fix(BA-67): service list CLI command always print image as (null) #3017 👈
• feat: Add canonical field to Image, ImageNode GQL API #3016
• main

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