feat: get/list Zitadel IdP (#12394)

# Which Problems Are Solved

This PR extends the functionality of `GetProviderByID`, `ListProviders`
v1 endpoints and `GetIDPByID` v2 endpoint to also return Zitadel IdP
when queried.

# How the Problems Are Solved

- Add `PROVIDER_TYPE_ZITADEL` and a `ZitadelConfig` to
`zitadel.idp.v1.ProviderConfig` (v1 APIs).
- Add `IDP_TYPE_ZITADEL`, `ZitadelConfig`, `InstanceRolesInfo` in v2
`idp.proto`
- Extend internal/query IDP template querying to include a
`ZitadelIDPTemplate` (incl. issuer, client credentials, scopes, instance
roles info).
- Add/extend integration tests for updating + fetching providers by ID
and listing providers.

# Additional Changes
N/A

# Additional Context
Closes https://github.com/zitadel/zitadel/issues/12051

---------

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

internal/command/instance_idp_test.go

@@ -6424,6 +6424,8 @@ func TestCommands_UpdateInstanceZitadelProvider(t *testing.T) {
 									KeyID:      "id",
 									Crypted:    []byte("newSecret"),
 								}),
+								idp.ChangeZitadelIDPInstanceRolesInfo(nil),
+								idp.ChangeZitadelIDPScopes(nil),
 							},
 						),
 					),
@@ -6489,6 +6491,17 @@ func TestCommands_UpdateInstanceZitadelProvider(t *testing.T) {
 					Name:     "name",
 					Issuer:   "issuer",
 					ClientID: "clientID",
+					Scopes:   []string{openid.ScopeOpenID, openid.ScopeEmail},
+					InstanceRolesInfo: []idp.RolesInfo{
+						{
+							OrganizationID:     "org1",
+							OrganizationDomain: "example-org1.com",
+						},
+						{
+							OrganizationID:     "org2",
+							OrganizationDomain: "example-org2.com",
+						},
+					},
 				},
 			},
 			res: res{
@@ -6756,7 +6769,7 @@ func TestCommands_UpdateInstanceZitadelProvider(t *testing.T) {
 					Issuer:       "new issuer",
 					ClientID:     "clientID2",
 					ClientSecret: "newSecret",
-					Scopes:       nil,
+					Scopes:       []string{openid.ScopeOpenID, openid.ScopeEmail},
 					IDPOptions: idp.Options{
 						IsCreationAllowed: true,
 						IsLinkingAllowed:  true,