Trimmed trailing = from UrlSafeBase64-encoded Node IDs (#9034)

Author: glen-84

src/HotChocolate/Core/src/Types/Types/Relay/Serialization/DefaultNodeIdSerializer.cs

@@ -216,6 +216,8 @@ static string FormatBase64(
                         span[i] = (byte)'_';
                     }
                 }
+
+                span = span.TrimEnd((byte)'=');
             }
 
             return ToString(span);

src/HotChocolate/Core/src/Types/Types/Relay/Serialization/OptimizedNodeIdSerializer.cs

@@ -472,6 +472,8 @@ private string FormatBase64(Span<byte> span, int written, bool urlSafeBase64, re
                         span[i] = (byte)'_';
                     }
                 }
+
+                span = span.TrimEnd((byte)'=');
             }
 
             return OptimizedNodeIdSerializer.ToString(span);

src/HotChocolate/Core/test/Types.Tests/Types/Relay/DefaultNodeIdSerializerTests.cs

@@ -48,7 +48,7 @@ public void Format_Small_StringId_UrlSafe()
         var value = Encoding.UTF8.GetString(Convert.FromBase64String("Rm9vOkberW9vVHlwZe+/vSs="));
         var id = serializer.Format("Foo", value);
 
-        Assert.Equal("Rm9vCmRGb286Rt6tb29UeXBl77-9Kw==", id);
+        Assert.Equal("Rm9vCmRGb286Rt6tb29UeXBl77-9Kw", id);
     }
 
     [Fact]