feat: create user scim v2 endpoint (#9132)

# Which Problems Are Solved
- Adds infrastructure code (basic implementation, error handling,
middlewares, ...) to implement the SCIM v2 interface
- Adds support for the user create SCIM v2 endpoint

# How the Problems Are Solved
- Adds support for the user create SCIM v2 endpoint under `POST
/scim/v2/{orgID}/Users`

# Additional Context

Part of #8140

internal/integration/client.go

@@ -17,6 +17,7 @@ import (
 	"google.golang.org/protobuf/types/known/structpb"
 
 	"github.com/zitadel/zitadel/internal/domain"
+	"github.com/zitadel/zitadel/internal/integration/scim"
 	"github.com/zitadel/zitadel/pkg/grpc/admin"
 	"github.com/zitadel/zitadel/pkg/grpc/auth"
 	"github.com/zitadel/zitadel/pkg/grpc/feature/v2"
@@ -67,6 +68,7 @@ type Client struct {
 	IDPv2          idp_pb.IdentityProviderServiceClient
 	UserV3Alpha    user_v3alpha.ZITADELUsersClient
 	SAMLv2         saml_pb.SAMLServiceClient
+	SCIM           *scim.Client
 }
 
 func newClient(ctx context.Context, target string) (*Client, error) {
@@ -99,6 +101,7 @@ func newClient(ctx context.Context, target string) (*Client, error) {
 		IDPv2:          idp_pb.NewIdentityProviderServiceClient(cc),
 		UserV3Alpha:    user_v3alpha.NewZITADELUsersClient(cc),
 		SAMLv2:         saml_pb.NewSAMLServiceClient(cc),
+		SCIM:           scim.NewScimClient(target),
 	}
 	return client, client.pollHealth(ctx)
 }