Support for account specific deploys

[McDoit]

Environment information

System:
  OS: Windows 10 10.0.19045
  CPU: (8) x64 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz
  Memory: 1.11 GB / 15.73 GB
Binaries:
  Node: 20.15.1 - C:\Program Files\nodejs\node.EXE
  Yarn: undefined - undefined
  npm: 10.7.0 - C:\Program Files\nodejs\npm.CMD
  pnpm: undefined - undefined
NPM Packages:
  @aws-amplify/auth-construct: 1.5.1
  @aws-amplify/backend: 1.10.0
  @aws-amplify/backend-auth: 1.4.2
  @aws-amplify/backend-cli: 1.4.4
  @aws-amplify/backend-data: 1.2.3
  @aws-amplify/backend-deployer: 1.1.12
  @aws-amplify/backend-function: 1.10.0
  @aws-amplify/backend-output-schemas: 1.4.0
  @aws-amplify/backend-output-storage: 1.1.4
  @aws-amplify/backend-secret: 1.1.5
  @aws-amplify/backend-storage: 1.2.4
  @aws-amplify/cli-core: 1.2.1
  @aws-amplify/client-config: 1.5.4
  @aws-amplify/deployed-backend-client: 1.5.0
  @aws-amplify/form-generator: 1.0.3
  @aws-amplify/model-generator: 1.0.10
  @aws-amplify/platform-core: 1.4.0
  @aws-amplify/plugin-types: 1.6.0
  @aws-amplify/sandbox: 1.2.8
  @aws-amplify/schema-generator: 1.2.6
  aws-amplify: 6.10.3
  aws-cdk: 2.173.2
  aws-cdk-lib: 2.173.2
  typescript: 5.7.2
No AWS environment variables
No CDK environment variables

Describe the feature

Related to #999 but didnt find any followup feature request for this

In dotnet i solved it by having this wrapper for the environment:

public class EnvironmentWrapper
{
    public static Amazon.CDK.Environment ConstructEnvironment(string account = null, string region = null)
    {
        return new Amazon.CDK.Environment
        {
            Account = System.Environment.GetEnvironmentVariable("CDK_DEPLOY_ACCOUNT") ??
                      account ??
                      System.Environment.GetEnvironmentVariable("CDK_DEFAULT_ACCOUNT"),
            Region = System.Environment.GetEnvironmentVariable("CDK_DEPLOY_REGION") ??
                     region ??
                     System.Environment.GetEnvironmentVariable("CDK_DEFAULT_REGION")
        };
    }
}

It provides a few ways of overriding it, or otherwise go for the default options of nothing, if no overrides are provided
Adding a typescript version like this to the creation of the AmplifyStack shouldn't break any existing deployments but add the possibility to go specific if needed

Use case

There is a few resources in CDK which you might rather want to do lookups for than hard code its value
My specific one now is VPC, to look up the one created by an outside CDK stack
But same applies for AMIs and parameters etc

[ykethan]

Thank you for filing this, marking as feature request.