Build and deploy CI stacks using npm through github actions

[Divyaasm]

Create a YAML workflow to manage the build and deployment of CI stacks. The workflow should have the following acceptance criteria:

On Pull Request Creation:

• Once the build is successful, generate a change-set for preview for the Beta environment to reflect the changes in the PR.

On Pull Request Merge:

• Wait for approval from admins after reviewing the change-set to deploy the stack in the Beta environment.
• Once approved, deploy the Beta stack.
• Generate a change set for the Prod AWS account to preview the changes.
• Wait for approval through the approval workflow.
• Once approved, deploy the stack using the previously created change set in the Prod environment.