patch 8.2.2501: not always clear where an error is reported

Problem:    Not always clear where an error is reported.
Solution:   Add the where_T structure and pass it around. (closes #7796)
diff --git a/src/errors.h b/src/errors.h
index 39eca7e..927e1ff 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -361,3 +361,5 @@
 	INIT(= N_("E1161: Cannot json encode a %s"));
 EXTERN char e_register_name_must_be_one_char_str[]
 	INIT(= N_("E1162: Register name must be one character: %s"));
+EXTERN char e_variable_nr_type_mismatch_expected_str_but_got_str[]
+	INIT(= N_("E1163: Variable %d: type mismatch, expected %s but got %s"));