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/api/http/header.go

@@ -5,6 +5,8 @@ import (
 	"net"
 	"net/http"
 	"strings"
+
+	"github.com/gorilla/mux"
 )
 
 const (
@@ -14,6 +16,7 @@ const (
 	CacheControl     = "cache-control"
 	ContentType      = "content-type"
 	ContentLength    = "content-length"
+	ContentLocation  = "content-location"
 	Expires          = "expires"
 	Location         = "location"
 	Origin           = "origin"
@@ -42,6 +45,9 @@ const (
 	PermissionsPolicy       = "permissions-policy"
 
 	ZitadelOrgID = "x-zitadel-orgid"
+
+	OrgIdInPathVariableName = "orgId"
+	OrgIdInPathVariable     = "{" + OrgIdInPathVariableName + "}"
 )
 
 type key int
@@ -104,6 +110,12 @@ func GetAuthorization(r *http.Request) string {
 }
 
 func GetOrgID(r *http.Request) string {
+	// path variable takes precedence over header
+	orgID, ok := mux.Vars(r)[OrgIdInPathVariableName]
+	if ok {
+		return orgID
+	}
+
 	return r.Header.Get(ZitadelOrgID)
 }