feat: mapper function for wish dto;

refactor: made guid foreign key for wish object for more ease of use

sqlc/schema.sql

@@ -111,6 +111,7 @@ CREATE TABLE IF NOT EXISTS "wishes" (
   id BIGSERIAL PRIMARY KEY,
   guid UUID UNIQUE NOT NULL DEFAULT gen_random_uuid(),
   wish_list_id BIGINT UNIQUE NOT NULL REFERENCES wish_lists(id) ON DELETE CASCADE,
+  wish_list_guid UUID NOT NULL REFERENCES wish_lists(guid) ON DELETE CASCADE,
   name VARCHAR(64) NOT NULL DEFAULT 'New wish',
   description VARCHAR(1000) NOT NULL DEFAULT '',
   picture_url VARCHAR(512) NOT NULL DEFAULT '',