feat(codegen): commit generated client types to codebase (#3492)

## What

Commit generated client types to codebase.

## Why

As a developer, we will provides better visibility on the impact of OAS changes to the generated type. Also allow for browser the types on GitHub.

## How

* Remove `/lib` from .gitignore
* Add a non-blocking github action check validating if the latest generated build has been committed.
  * Runs `yarn build --force --no-cache` on GitHub. Caching was creating false positives.
  * Use `git status` and filter the output to target only `packages/generated` directory. 

## Test

Proof of a failing check:
https://github.com/medusajs/medusa/actions/runs/4432323763/jobs/7776235128

UPDATE: Failing check after updating branch with latest develop
https://github.com/medusajs/medusa/actions/runs/4436707954/jobs/7785472045

.github/workflows/codegen-test.yml

@@ -0,0 +1,40 @@
+name: OAS Codegen Build Check - BETA
+on:
+  pull_request:
+    paths-ignore:
+      - "docs/**"
+      - "www/**"
+
+jobs:
+  codegen-test:
+    runs-on: ubuntu-latest
+    env:
+      TURBO_TOKEN: ${{ secrets.TURBO_TOKEN }}
+      TURBO_TEAM: ${{ secrets.TURBO_TEAM }}
+    steps:
+      - name: Cancel Previous Runs
+        uses: styfle/cancel-workflow-action@0.9.1
+        with:
+          access_token: ${{ github.token }}
+
+      - name: Checkout
+        uses: actions/checkout@v2.3.5
+        with:
+          fetch-depth: 0
+
+      - name: Setup Node.js environment
+        uses: actions/setup-node@v2.4.1
+        with:
+          node-version: "14"
+          cache: "yarn"
+
+      - name: Install dependencies
+        uses: ./.github/actions/cache-deps
+        with:
+          extension: codegen
+
+      - name: Build Packages - Force
+        run: yarn build --force --no-cache
+
+      - name: Assert latest codegen build committed
+        run: ./scripts/assert-codegen-build-committed-actions.sh