Add District entity and update GeocoderController

to include District information

src/FunderMaps.Core/Entities/District.cs

@@ -0,0 +1,44 @@
+using FunderMaps.Core.DataAnnotations;
+using System.ComponentModel.DataAnnotations;
+
+namespace FunderMaps.Core.Entities;
+
+/// <summary>
+///     District entity.
+/// </summary>
+public sealed class District : IEntityIdentifier<string>
+{
+    /// <summary>
+    ///     Entity identifier.
+    /// </summary>
+    public string Identifier => Id;
+
+    /// <summary>
+    ///     Unique identifier.
+    /// </summary>
+    [Required, Geocoder]
+    public string Id { get; set; } = default!;
+
+    /// <summary>
+    ///     District name.
+    /// </summary>
+    [Required]
+    public string Name { get; set; } = default!;
+
+    /// <summary>
+    ///    Is water district.
+    /// </summary>
+    public bool Water { get; set; }
+
+    /// <summary>
+    ///     External data source id.
+    /// </summary>
+    [Required]
+    public string ExternalId { get; set; } = default!;
+
+    /// <summary>
+    ///     Municipality identifier.
+    /// </summary>
+    [Geocoder]
+    public string? MunicipalityId { get; set; }
+}

src/FunderMaps.WebApi/Controllers/GeocoderController.cs

@@ -10,7 +10,7 @@ public sealed class GeocoderInfo
     public Building Building { get; set; } = default!;
     public Address Address { get; set; } = default!;
     public Neighborhood? Neighborhood { get; set; }
-    // TODO: Add Wijk
+    public District? District { get; set; }
     // TODO: Add Municipality
     // TODO: Add Province
 }
@@ -56,7 +56,7 @@ public Task<Neighborhood> GetNeighborhoodAsync(string id)
 
     // GET: api/geocoder/{id}
     /// <summary>
-    ///     Get building by identifier.
+    ///     Get geocoder information by identifier.
     /// </summary>
     /// <remarks>
     ///     Cache response for 8 hours. Building will not change often.