feat: add custom org ID to AddOrganizationRequest (#9720)

# Which Problems Are Solved

- It is not possible to specify a custom organization ID when creating
an organization. According to
https://github.com/zitadel/zitadel/discussions/9202#discussioncomment-11929464
this is "an inconsistency in the V2 API".

# How the Problems Are Solved

- Adds the `org_id` as an optional parameter to the
`AddOrganizationRequest` in the `v2beta` API.

# Additional Changes

None. 

# Additional Context

- Discussion
[#9202](https://github.com/zitadel/zitadel/discussions/9202)
- I was mostly interested in how much work it'd be to add this field.
Then after completing this, I thought I'd submit this PR. I won't be
angry if you just close this PR with the reasoning "we didn't ask for
it". 😄
- Even though I don't think this is a breaking change, I didn't add this
to the `v2` API yet (don't know what the process for this is TBH). The
changes should be analogous, so if you want me to, just request it.

---------

Co-authored-by: Stefan Benz <46600784+stebenz@users.noreply.github.com>

internal/command/org.go

@@ -31,6 +31,7 @@ type OrgSetup struct {
 	Name         string
 	CustomDomain string
 	Admins       []*OrgSetupAdmin
+	OrgID        string
 }
 
 // OrgSetupAdmin describes a user to be created (Human / Machine) or an existing (ID) to be used for an org setup.
@@ -64,6 +65,13 @@ type CreatedOrgAdmin struct {
 	MachineKey *MachineKey
 }
 
+func (o *OrgSetup) Validate() (err error) {
+	if o.OrgID != "" && strings.TrimSpace(o.OrgID) == "" {
+		return zerrors.ThrowInvalidArgument(nil, "ORG-4ABd3", "Errors.Invalid.Argument")
+	}
+	return nil
+}
+
 func (c *Commands) setUpOrgWithIDs(ctx context.Context, o *OrgSetup, orgID string, allowInitialMail bool, userIDs ...string) (_ *CreatedOrg, err error) {
 	cmds := c.newOrgSetupCommands(ctx, orgID, o)
 	for _, admin := range o.Admins {
@@ -233,12 +241,19 @@ func (c *orgSetupCommands) createdMachineAdmin(admin *OrgSetupAdmin) *CreatedOrg
 }
 
 func (c *Commands) SetUpOrg(ctx context.Context, o *OrgSetup, allowInitialMail bool, userIDs ...string) (*CreatedOrg, error) {
-	orgID, err := c.idGenerator.Next()
-	if err != nil {
+	if err := o.Validate(); err != nil {
 		return nil, err
 	}
 
-	return c.setUpOrgWithIDs(ctx, o, orgID, allowInitialMail, userIDs...)
+	if o.OrgID == "" {
+		var err error
+		o.OrgID, err = c.idGenerator.Next()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return c.setUpOrgWithIDs(ctx, o, o.OrgID, allowInitialMail, userIDs...)
 }
 
 // AddOrgCommand defines the commands to create a new org,

internal/command/org_test.go

@@ -1344,6 +1344,22 @@ func TestCommandSide_SetUpOrg(t *testing.T) {
 				err: zerrors.ThrowInvalidArgument(nil, "ORG-mruNY", "Errors.Invalid.Argument"),
 			},
 		},
+		{
+			name: "org id empty, error",
+			fields: fields{
+				eventstore: expectEventstore(),
+			},
+			args: args{
+				ctx: http_util.WithRequestedHost(context.Background(), "iam-domain"),
+				setupOrg: &OrgSetup{
+					Name:  "Org",
+					OrgID: " ",
+				},
+			},
+			res: res{
+				err: zerrors.ThrowInvalidArgument(nil, "ORG-4ABd3", "Errors.Invalid.Argument"),
+			},
+		},
 		{
 			name: "userID not existing, error",
 			fields: fields{
@@ -1523,6 +1539,45 @@ func TestCommandSide_SetUpOrg(t *testing.T) {
 				},
 			},
 		},
+		{
+			name: "no human added, custom org ID",
+			fields: fields{
+				eventstore: expectEventstore(
+					expectPush(
+						eventFromEventPusher(org.NewOrgAddedEvent(context.Background(),
+							&org.NewAggregate("custom-org-ID").Aggregate,
+							"Org",
+						)),
+						eventFromEventPusher(org.NewDomainAddedEvent(context.Background(),
+							&org.NewAggregate("custom-org-ID").Aggregate, "org.iam-domain",
+						)),
+						eventFromEventPusher(org.NewDomainVerifiedEvent(context.Background(),
+							&org.NewAggregate("custom-org-ID").Aggregate,
+							"org.iam-domain",
+						)),
+						eventFromEventPusher(org.NewDomainPrimarySetEvent(context.Background(),
+							&org.NewAggregate("custom-org-ID").Aggregate,
+							"org.iam-domain",
+						)),
+					),
+				),
+			},
+			args: args{
+				ctx: http_util.WithRequestedHost(context.Background(), "iam-domain"),
+				setupOrg: &OrgSetup{
+					Name:  "Org",
+					OrgID: "custom-org-ID",
+				},
+			},
+			res: res{
+				createdOrg: &CreatedOrg{
+					ObjectDetails: &domain.ObjectDetails{
+						ResourceOwner: "custom-org-ID",
+					},
+					CreatedAdmins: []*CreatedOrgAdmin{},
+				},
+			},
+		},
 		{
 			name: "existing human added",
 			fields: fields{