ds: array: update to_string() to surround string values in quotes

ds/array.c

@@ -1,6 +1,7 @@
 #include <blue/core/iterator.h>
 #include <blue/core/stream.h>
 #include <blue/ds/array.h>
+#include <blue/ds/string.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -323,8 +324,7 @@ static void array_to_string(const b_object *obj, b_stream *out)
 
 	for (size_t i = 0; i < array->ar_len; i++) {
 		b_object *value = array->ar_data[i];
-		bool is_string
-			= false;   // b_object_is_type(value, B_TYPE_STRING);
+		bool is_string = b_object_is_type(value, B_TYPE_STRING);
 
 		if (is_string) {
 			b_stream_write_char(out, '"');