Removed azimuthal and "auto" map projections

Removing these projections - which were never really well implemented - greatly simplifies the code. There is no ProjectionCenter anymore and MapProjection methods do not return null Locations or Points.

MapControl/Shared/StereographicProjection.cs

@@ -1,53 +0,0 @@
-using System;
-#if WPF
-using System.Windows;
-using System.Windows.Media;
-#elif AVALONIA
-using Avalonia;
-#endif
-
-namespace MapControl
-{
-    /// <summary>
-    /// Spherical Stereographic Projection - AUTO2:97002.
-    /// See "Map Projections - A Working Manual" (https://pubs.usgs.gov/publication/pp1395), p.157-160.
-    /// </summary>
-    public class StereographicProjection : AzimuthalProjection
-    {
-        public const string DefaultCrsId = "AUTO2:97002"; // GeoServer non-standard CRS identifier
-
-        public StereographicProjection() // parameterless constructor for XAML
-            : this(DefaultCrsId)
-        {
-        }
-
-        public StereographicProjection(string crsId)
-        {
-            CrsId = crsId;
-        }
-
-        public override Matrix RelativeTransform(double latitude, double longitude)
-        {
-            var p = GetProjectedPoint(latitude, longitude);
-            var k = 2d / (1d + p.CosC); // p.157 (21-4), k0 == 1
-
-            return RelativeTransform(latitude, longitude, k, k);
-        }
-
-        public override Point? LocationToMap(double latitude, double longitude)
-        {
-            var p = GetProjectedPoint(latitude, longitude);
-            var k = 2d / (1d + p.CosC); // p.157 (21-4), k0 == 1
-
-            return new Point(EquatorialRadius * k * p.X, EquatorialRadius * k * p.Y); // p.157 (21-2/3)
-        }
-
-        public override Location MapToLocation(double x, double y)
-        {
-            var rho = Math.Sqrt(x * x + y * y);
-            var c = 2d * Math.Atan(rho / (2d * EquatorialRadius)); // p.159 (21-15), k0 == 1
-
-            return GetLocation(x, y, rho, Math.Sin(c));
-        }
-    }
-}