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/dict.c b/src/dict.c
index c2dc6a7..88cc4b3 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -649,6 +649,15 @@
 }
 
 /*
+ * Returns TRUE if "key" is present in Dictionary "d".
+ */
+    int
+dict_has_key(dict_T *d, char *key)
+{
+    return dict_find(d, (char_u *)key, -1) != NULL;
+}
+
+/*
  * Get a typval_T item from a dictionary and copy it into "rettv".
  * Returns FAIL if the entry doesn't exist or out of memory.
  */
@@ -1582,8 +1591,8 @@
     if (argvars[0].vval.v_dict == NULL)
 	return;
 
-    rettv->vval.v_number = dict_find(argvars[0].vval.v_dict,
-				      tv_get_string(&argvars[1]), -1) != NULL;
+    rettv->vval.v_number = dict_has_key(argvars[0].vval.v_dict,
+				(char *)tv_get_string(&argvars[1]));
 }
 
 #endif // defined(FEAT_EVAL)