Add more test cases.

Author: Cesar Blum Silveira

test/Microsoft.AspNetCore.Server.KestrelTests/FrameResponseHeadersTests.cs

@@ -269,6 +269,7 @@ private static long ParseLong(string value)
             "00",
             "042",
             "42",
+            long.MaxValue.ToString(CultureInfo.InvariantCulture)
         };
 
         public static TheoryData<string> BadContentLengths => new TheoryData<string>
@@ -278,6 +279,11 @@ private static long ParseLong(string value)
             " 42",
             "42 ",
             "bad",
+            "!",
+            "!42",
+            "42!",
+            "42,000",
+            "42.000",
         };
     }
 }