refactor(medusa): move repository specs into its own folder (#2952)

**What:**

Introduces a new folder under which repository specs will be placed. 

Why:

We don't currently have a good place to test ORM logic or custom queries against the database. The repository folder tests are a place for just exactly that. 

How:

Creates an internal package similar to other integration tests - api and plugins. 

CORE-965

integration-tests/repositories/medusa-config.js

@@ -0,0 +1,15 @@
+const DB_HOST = process.env.DB_HOST
+const DB_USERNAME = process.env.DB_USERNAME
+const DB_PASSWORD = process.env.DB_PASSWORD
+const DB_NAME = process.env.DB_TEMP_NAME
+
+module.exports = {
+  plugins: [],
+  projectConfig: {
+    redis_url: process.env.REDIS_URL,
+    database_url: `postgres://${DB_USERNAME}:${DB_PASSWORD}@${DB_HOST}/${DB_NAME}`,
+    database_type: "postgres",
+    jwt_secret: "test",
+    cookie_secret: "test",
+  },
+}