If the LSL state_entry() event definition contains any parameters, then generate syntax error as seen on the LL grid

This is done through the parser and so generates the same syntax error message if any parameters are wrongly specified for this event.
We were already enforcing event names in the parser.
This is only for state_entry so far as an initial test of the approach - appears to work correctly.

OpenSim/Region/ScriptEngine/Shared/CodeTools/Tests/CSCodeGeneratorTest.cs

@@ -762,6 +762,7 @@ default
         public void TestIfStatement()
         {
             TestHelpers.InMethod();
+//            TestHelpers.EnableLogging();
 
             string input = @"// let's test if statements