patch 8.2.4683: verbose check with dict_find() to see if a key is present

Problem:    Verbose check with dict_find() to see if a key is present.
Solution:   Add dict_has_key(). (Yegappan Lakshmanan, closes #10074)
diff --git a/src/time.c b/src/time.c
index 00275ef..53ac853 100644
--- a/src/time.c
+++ b/src/time.c
@@ -848,7 +848,7 @@
 	    semsg(_(e_invalid_argument_str), tv_get_string(&argvars[2]));
 	    return;
 	}
-	if (dict_find(dict, (char_u *)"repeat", -1) != NULL)
+	if (dict_has_key(dict, "repeat"))
 	    repeat = dict_get_number(dict, (char_u *)"repeat");
     }