fix: Fixes sending packets and sidesteps a major issue with stackalloc and PGO in .NET 8 (#1607)

### Summary
- Works around a sneaky edge case bug in the JIT with stackalloc where sometimes the buffer is not zero'd.
- Fixes SendDisplayBoatHS
- Fixes sending health bars in the `SendEverything()` logic.
- Fixes a bug in sizing for some string helper functions.

### Developer Note
We are enabled `SkipLocalsInit` - do not rely on `stackalloc` to be zero'd. To zero the buffer, use `span.Clear();`

Closes #1606

Projects/Server/Network/Packets/OutgoingMobilePackets.cs

@@ -604,9 +604,7 @@ public static class OutgoingMobilePackets
         }
 
         Span<bool> layers = stackalloc bool[256];
-#if NO_LOCAL_INIT
-            layers.Clear();
-#endif
+        layers.Clear();
 
         var eq = beheld.Items;
         var maxLength = 23 + (eq.Count + 2) * 9;