Setup test, break apart entrypoint, & align GHA workflow

backend/test-resources/docker-compose.test.yml

@@ -0,0 +1,12 @@
+version: '3'
+
+services:
+  mongo-test:
+    image: mongo
+    container_name: infisical-test-mongo
+    restart: always
+    ports:
+      - 27018:27017
+    environment:
+      - MONGO_INITDB_ROOT_USERNAME=test
+      - MONGO_INITDB_ROOT_PASSWORD=test1234

backend/test-resources/env-vars.js

@@ -0,0 +1,5 @@
+/* eslint-disable no-undef */
+process.env.MONGO_URL =
+  'mongodb://test:test1234@localhost:27018/?authSource=admin';
+process.env.MONGO_USERNAME = 'test';
+process.env.MONGO_PASSWORD = 'test1234';