feat: extend DeleteProvider to include Zitadel IdP (#12396)

# Which Problems Are Solved

This PR extends `DeleteProvider` to include Zitadel provider enabling
the deletion of Zitadel IdP.

# How the Problems Are Solved

- Extend org/instance IDP remove write models to include
`ZitadelIDPAddedEvent` in event appends and queries.
- Extend command-side IDP reduction/type handling for Zitadel IDP add
events.
- Add management/admin integration tests for deleting Zitadel providers
- Add error translation key in all language locales for org-level “IDP
config not existing”.

# Additional Changes

N/A

# Additional Context.
Closes https://github.com/zitadel/zitadel/issues/12397

---------

Co-authored-by: Copilot Autofix powered by AI <[email protected]>
Co-authored-by: Livio Spring <[email protected]>

internal/command/instance_idp_model.go

@@ -998,6 +998,8 @@ func (wm *InstanceIDPRemoveWriteModel) AppendEvents(events ...eventstore.Event)
 			wm.IDPRemoveWriteModel.AppendEvents(&e.IDPConfigAddedEvent)
 		case *instance.IDPConfigRemovedEvent:
 			wm.IDPRemoveWriteModel.AppendEvents(&e.IDPConfigRemovedEvent)
+		case *instance.ZitadelIDPAddedEvent:
+			wm.IDPRemoveWriteModel.AppendEvents(&e.ZitadelIDPAddedEvent)
 		default:
 			wm.IDPRemoveWriteModel.AppendEvents(e)
 		}
@@ -1023,6 +1025,7 @@ func (wm *InstanceIDPRemoveWriteModel) Query() *eventstore.SearchQueryBuilder {
 			instance.LDAPIDPAddedEventType,
 			instance.AppleIDPAddedEventType,
 			instance.SAMLIDPAddedEventType,
+			instance.ZitadelIDPAddedEventType,
 			instance.IDPRemovedEventType,
 		).
 		EventData(map[string]interface{}{"id": wm.ID}).