feat: initial test suite framework (#4929)

jest.config.js

@@ -1,9 +1,10 @@
-module.exports = {
+const customJestConfig = {
   globalSetup: './test/jest.setup.ts',
   moduleNameMapper: {
     '\\.(css|scss)$': '<rootDir>/packages/payload/src/bundlers/mocks/emptyModule.js',
     '\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$':
       '<rootDir>/packages/payload/src/bundlers/mocks/fileMock.js',
+    'payload-config': '<rootDir>/__mocks__/payload-config.ts',
   },
   testEnvironment: 'node',
   testMatch: ['<rootDir>/packages/payload/src/**/*.spec.ts', '<rootDir>/test/**/*int.spec.ts'],
@@ -13,3 +14,5 @@ module.exports = {
   },
   verbose: true,
 }
+
+module.exports = customJestConfig