[gpctl] parsing error when running `gpctl workspaces describe <instanceID>`

[kylos101]

Description

gpctl workspaces describe <instance-id> returns a parsing error when the instance ID is valid

How to recreate

Scenario 1: a running workspace

kyle@work:~$ gpctl workspaces describe 8ea27a2a-2b6c-4a5d-87ef-31f341a2d1cb
Owner:            4dff9b27-45c2-4bb9-83af-0ae44b46a6b5
Workspace:        4geeksacademy-reacttutor-3e5u57gscjz
Instance:         8ea27a2a-2b6c-4a5d-87ef-31f341a2d1cb
Phase:            RUNNING
Conditions:
FATA[0000] template: prettyprint:9:31: executing "prettyprint" at <.Conditions.ServiceExists>: can't evaluate field ServiceExists in type *api.WorkspaceConditions 

Scenario 2: a stopping workspace

kyle@work:~$ gpctl workspaces describe b3df4c9e-74a1-4317-a34f-42049678f95e
FATA[0000] template: prettyprint:9:31: executing "prettyprint" at <.Conditions.ServiceExists>: can't evaluate field ServiceExists in type *api.WorkspaceConditions 

Expected behavior

No parsing error

Bonus

If possible, return the phase history of the instance, so we can see how long it spent in each phase.