libyang MAINTENANCE cleanup header includes

Use iwyu tool and fix which headers are included
diff --git a/src/parser_yang.c b/src/parser_yang.c
index e9e1a82..6e38e2c 100644
--- a/src/parser_yang.c
+++ b/src/parser_yang.c
@@ -30,11 +30,12 @@
 #include "path.h"
 #include "set.h"
 #include "tree.h"
-#include "tree_data_internal.h"
 #include "tree_edit.h"
 #include "tree_schema.h"
 #include "tree_schema_internal.h"
 
+struct lys_glob_unres;
+
 /**
  * @brief Insert WORD into the libyang context's dictionary and store as TARGET.
  * @param[in] CTX yang parser context to access libyang context.