Add endpoint to access and modify user information.

Marechai.Data/Models/UserRoleRequest.cs

@@ -0,0 +1,11 @@
+using System.ComponentModel.DataAnnotations;
+using System.Text.Json.Serialization;
+
+namespace Marechai.Data.Models;
+
+public sealed record UserRoleRequest
+{
+    [Required]
+    [JsonPropertyName("roleName")]
+    public string RoleName { get; set; } = null!;
+}