New GDScript tokenizer and parser

Sometimes to fix something you have to break it first.

This get GDScript mostly working with the new tokenizer and parser but
a lot of things isn't working yet. It compiles and it's usable, and that
should be enough for now.

Don't worry: other huge commits will come after this.

modules/gdscript/language_server/gdscript_text_document.h

@@ -31,6 +31,9 @@
 #ifndef GDSCRIPT_TEXT_DOCUMENT_H
 #define GDSCRIPT_TEXT_DOCUMENT_H
 
+// FIXME: Reenable LSP.
+#if 0
+
 #include "core/os/file_access.h"
 #include "core/reference.h"
 #include "lsp.hpp"
@@ -76,3 +79,5 @@ public:
 };
 
 #endif
+
+#endif