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/scim/schemas/url.go

@@ -0,0 +1,50 @@
+package schemas
+
+import (
+	"encoding/json"
+	"net/url"
+
+	"github.com/zitadel/zitadel/internal/zerrors"
+)
+
+type HttpURL url.URL
+
+func ParseHTTPURL(rawURL string) (*HttpURL, error) {
+	parsedURL, err := url.Parse(rawURL)
+	if err != nil {
+		return nil, err
+	}
+
+	if parsedURL.Scheme != "http" && parsedURL.Scheme != "https" {
+		return nil, zerrors.ThrowInvalidArgumentf(nil, "SCIM-htturl1", "HTTP URL expected, got %v", parsedURL.Scheme)
+	}
+
+	return (*HttpURL)(parsedURL), nil
+}
+
+func (u *HttpURL) UnmarshalJSON(data []byte) error {
+	var urlStr string
+	if err := json.Unmarshal(data, &urlStr); err != nil {
+		return err
+	}
+
+	parsedURL, err := ParseHTTPURL(urlStr)
+	if err != nil {
+		return err
+	}
+
+	*u = *parsedURL
+	return nil
+}
+
+func (u *HttpURL) MarshalJSON() ([]byte, error) {
+	return json.Marshal(u.String())
+}
+
+func (u *HttpURL) String() string {
+	if u == nil {
+		return ""
+	}
+
+	return (*url.URL)(u).String()
+}