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/jest.config.js

@@ -0,0 +1,21 @@
+module.exports = {
+  name: "repositories",
+  testEnvironment: `node`,
+  rootDir: "./",
+  testTimeout: 10000,
+  testPathIgnorePatterns: [
+    `/examples/`,
+    `/www/`,
+    `/dist/`,
+    `/node_modules/`,
+    `__tests__/fixtures`,
+    `__testfixtures__`,
+    `.cache`,
+  ],
+  transformIgnorePatterns: [`/dist`],
+  transform: { "^.+\\.[jt]s$": `../../jest-transformer.js` },
+  setupFiles: ["../setup-env.js"],
+  setupFilesAfterEnv: ["../setup.js"],
+  globalSetup: "../globalSetup.js",
+  globalTeardown: "../globalTeardown.js",
+}