chore: Refactor run_integration_tests.sh by adding stack language check

[lym953]

Background

• integration_tests/stacks/ contains a few example Typescript stacks
• integration_tests/snapshots/ contains the expected snapshots generated from the stacks
• scripts/run_integration_tests.sh generates snapshots from the stacks, and compare the generated stacks with expected stacks

Motivation

The test only covers TypeScript stacks. We want to cover Python and Go stacks as well to prevent issues like https://github.com/DataDog/datadog-cdk-constructs/issues/294, where the Python package was broken.

What does this PR do?

1. Move the Typescript stacks to a typescript/ directory
2. Make run_integration_tests.sh check the language of each stack, instead of assuming all stacks are in Typescript. Make the script require that path of a typescript stack should be like typescript/<name>.ts.

Testing Guidelines

Run aws-vault exec sso-serverless-sandbox-account-admin -- scripts/run_integration_tests.sh. It finished successfully and the output was same as before.

Additional Notes

Types of Changes

• [ ] Bug fix
• [ ] New feature
• [ ] Breaking change
• [x] Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• [x] This PR's description is comprehensive
• [ ] This PR contains breaking changes that are documented in the description
• [ ] This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• [ ] This PR impacts documentation, and it has been updated (or a ticket has been logged)
• [ ] This PR's changes are covered by the automated tests
• [ ] This PR collects user input/sensitive content into Datadog