patch 8.2.3970: error messages are spread out

Problem:    Error messages are spread out.
Solution:   Move more errors to errors.h.
diff --git a/src/dict.c b/src/dict.c
index 0c9cea3..b3cdfd9 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -962,7 +962,7 @@
 	    if (*skipwhite(*arg) == ':')
 		semsg(_(e_no_white_space_allowed_before_str_str), ":", *arg);
 	    else
-		semsg(_(e_missing_dict_colon), *arg);
+		semsg(_(e_missing_colon_in_dictionary), *arg);
 	    clear_tv(&tvkey);
 	    goto failret;
 	}
@@ -1002,7 +1002,7 @@
 	    item = dict_find(d, key, -1);
 	    if (item != NULL)
 	    {
-		semsg(_(e_duplicate_key), key);
+		semsg(_(e_duplicate_key_in_dicitonary), key);
 		clear_tv(&tvkey);
 		clear_tv(&tv);
 		goto failret;
@@ -1042,7 +1042,7 @@
 	    if (**arg == ',')
 		semsg(_(e_no_white_space_allowed_before_str_str), ",", *arg);
 	    else
-		semsg(_(e_missing_dict_comma), *arg);
+		semsg(_(e_missing_comma_in_dictionary), *arg);
 	    goto failret;
 	}
     }