Cleanup text after calling GetTextInfo

Turns out GetTextInfo changes text internally and because TextBoxTMP#GiveFocus now sets caretPos based on text length it was causing crashes.

Reactor/Patches/Fixes/CursorPosPatch.cs

@@ -23,6 +23,7 @@ public static bool Prefix(TextMeshPro self, ref Vector2 __result)
         if (self.textInfo == null || self.textInfo.lineCount == 0 || self.textInfo.lineInfo[0].characterCount <= 0)
         {
             __result = self.GetTextInfo(" ").lineInfo.First().lineExtents.max;
+            self.text = string.Empty;
             return false;
         }