Close #15750: Multiple park entrance types in one park (#21909)

* Add new park entrance placement window

* Start entrance tool as soon as window opens;

* Rename constants to conform to current code standards

* Increment PARK_FILE_CURRENT_VERSION

* Increment kNetworkStreamVersion

Co-authored-by: Aaron van Geffen <aaron@aaronweb.net>

src/openrct2-ui/WindowManager.cpp

@@ -144,6 +144,8 @@ public:
                 return TransparencyOpen();
             case WindowClass::AssetPacks:
                 return AssetPacksOpen();
+            case WindowClass::EditorParkEntrance:
+                return EditorParkEntranceOpen();
             default:
                 Console::Error::WriteLine("Unhandled window class (%d)", wc);
                 return nullptr;