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_language_server.h

@@ -31,6 +31,9 @@
 #ifndef GDSCRIPT_LANGUAGE_SERVER_H
 #define GDSCRIPT_LANGUAGE_SERVER_H
 
+// FIXME: Reenable LSP.
+#if 0
+
 #include "../gdscript_parser.h"
 #include "editor/editor_plugin.h"
 #include "gdscript_language_protocol.h"
@@ -60,4 +63,6 @@ public:
 
 void register_lsp_types();
 
+#endif
+
 #endif // GDSCRIPT_LANGUAGE_SERVER_H