Goal

Fix GitOps Engine code to honor Impersonate configuration set in the Application sync context for all kubectl commands that are being executed.

Acceptance Criteria:

• It should be possible for the GitOps Engine to run application sync using impersonation config.
• When impersonation config is not set, then the existing behaviour of using the control-plane service account for the sync operation must be the default behaviour.
• If there is error in the impersonation configuration, then error with appropriate message should be reported.
• If the impersonating user does not have sufficient permissions for the application sync to happen, then the sync operation should fail with an appropriate error message.