feat: Sync Events no longer need Event prefix (#2087)

Instead of doing
```cs
[SyncEvent]
public event MySyncEventDelegate EventOnly;
```

You can now do
```cs
[SyncEvent]
public event MySyncEventDelegate Only;
```

We actually tried to remove them a while ago. The way the weaver worked
back then caused an infinite recursion.

Since the Command rewrite that allows virtuals, this is no longer
a problem.  So we can drop this requirement.

Co-authored-by: Paul Pacheco <paul.pacheco@aa.com>

Assets/Mirror/Editor/Weaver/Processors/SyncEventProcessor.cs

@@ -118,12 +118,6 @@ public static void ProcessEvents(TypeDefinition td, List<EventDefinition> events
 
                 if (syncEventAttr != null)
                 {
-                    if (!ed.Name.StartsWith("Event"))
-                    {
-                        Weaver.Error($"{ed.Name} must start with Event.  Consider renaming it to Event{ed.Name}", ed);
-                        return;
-                    }
-
                     if (ed.EventType.Resolve().HasGenericParameters)
                     {
                         Weaver.Error($"{ed.Name} must not have generic parameters.  Consider creating a new class that inherits from {ed.EventType} instead", ed);

Assets/Mirror/Tests/Editor/SyncEventTest.cs

@@ -9,11 +9,11 @@ namespace Mirror.Tests.RemoteAttrributeTest
     class SyncEventBehaviour : NetworkBehaviour
     {
         [SyncEvent]
-        public event MySyncEventDelegate EventOnly;
+        public event MySyncEventDelegate Only;
 
         public void CallEvent(int i)
         {
-            EventOnly.Invoke(i);
+            Only.Invoke(i);
         }
     }
 
@@ -51,7 +51,7 @@ public void FirstEventIsCalled()
             const int someInt = 20;
 
             int callCount = 0;
-            clientBehaviour.EventOnly += incomingInt =>
+            clientBehaviour.Only += incomingInt =>
             {
                 callCount++;
                 Assert.That(incomingInt, Is.EqualTo(someInt));

Assets/Mirror/Tests/Editor/Weaver/WeaverSyncEventTests.cs

@@ -16,14 +16,6 @@ public void MultipleSyncEvent()
             Assert.That(weaverErrors, Is.Empty);
         }
 
-        [Test]
-        public void ErrorWhenSyncEventDoesntStartWithEvent()
-        {
-            Assert.That(weaverErrors, Contains.Item("DoCoolThingsWithExcitingPeople must start with Event.  " +
-                "Consider renaming it to EventDoCoolThingsWithExcitingPeople " +
-                "(at WeaverSyncEventTests.ErrorWhenSyncEventDoesntStartWithEvent.ErrorWhenSyncEventDoesntStartWithEvent/MySyncEventDelegate WeaverSyncEventTests.ErrorWhenSyncEventDoesntStartWithEvent.ErrorWhenSyncEventDoesntStartWithEvent::DoCoolThingsWithExcitingPeople)"));
-        }
-
         [Test]
         public void ErrorWhenSyncEventUsesGenericParameter()
         {