…uct (#31107)

### Issue # (if applicable)

#8581.

### Reason for this change

It is easier and clearer to specify the SNS Topic ARNs on the stack construct itself instead of passing it as a command line argument.

### Description of changes

Added a new optional stack prop, `notificationArns`, that is written to the CloudAssembly and concatenated with the CLI option `--notification-arns`. 

Don't forget to select stacks by hierarchical ID (currently display name, in our tests) when writing certain test code. Otherwise, the tests may not select the stack you expect.

Depends on: cdklabs/cdk-assets#87 and cdklabs/cloud-assembly-schema#58.

### Description of how you validated changes

Unit tests + CLI integ test. Framework integ tests not included because they would require an externally-created SNS Topic, which is not what we want in integ tests; besides, the case is covered by the CLI integ test. 

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

…uct (aws#31107)

### Issue # (if applicable)

aws#8581.

### Reason for this change

It is easier and clearer to specify the SNS Topic ARNs on the stack construct itself instead of passing it as a command line argument.

### Description of changes

Added a new optional stack prop, `notificationArns`, that is written to the CloudAssembly and concatenated with the CLI option `--notification-arns`. 

Don't forget to select stacks by hierarchical ID (currently display name, in our tests) when writing certain test code. Otherwise, the tests may not select the stack you expect.

Depends on: cdklabs/cdk-assets#87 and cdklabs/cloud-assembly-schema#58.

### Description of how you validated changes

Unit tests + CLI integ test. Framework integ tests not included because they would require an externally-created SNS Topic, which is not what we want in integ tests; besides, the case is covered by the CLI integ test. 

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

…uct (aws#31107)

It is easier and clearer to specify the SNS Topic ARNs on the stack construct itself instead of passing it as a command line argument.

Added a new optional stack prop, `notificationArns`, that is written to the CloudAssembly and concatenated with the CLI option `--notification-arns`.

Don't forget to select stacks by hierarchical ID (currently display name, in our tests) when writing certain test code. Otherwise, the tests may not select the stack you expect.

Depends on: cdklabs/cdk-assets#87 and cdklabs/cloud-assembly-schema#58.

Unit tests + CLI integ test. Framework integ tests not included because they would require an externally-created SNS Topic, which is not what we want in integ tests; besides, the case is covered by the CLI integ test.

- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

…uct (#31107)

It is easier and clearer to specify the SNS Topic ARNs on the stack construct itself instead of passing it as a command line argument.

Added a new optional stack prop, `notificationArns`, that is written to the CloudAssembly and concatenated with the CLI option `--notification-arns`.

Don't forget to select stacks by hierarchical ID (currently display name, in our tests) when writing certain test code. Otherwise, the tests may not select the stack you expect.

Depends on: cdklabs/cdk-assets#87 and cdklabs/cloud-assembly-schema#58.

Unit tests + CLI integ test. Framework integ tests not included because they would require an externally-created SNS Topic, which is not what we want in integ tests; besides, the case is covered by the CLI integ test.

- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

…uct (#31107)

### Issue # (if applicable)

#8581.

### Reason for this change

It is easier and clearer to specify the SNS Topic ARNs on the stack construct itself instead of passing it as a command line argument.

### Description of changes

Added a new optional stack prop, `notificationArns`, that is written to the CloudAssembly and concatenated with the CLI option `--notification-arns`. 

Don't forget to select stacks by hierarchical ID (currently display name, in our tests) when writing certain test code. Otherwise, the tests may not select the stack you expect.

Depends on: cdklabs/cdk-assets#87 and cdklabs/cloud-assembly-schema#58.

### Description of how you validated changes

Unit tests + CLI integ test. Framework integ tests not included because they would require an externally-created SNS Topic, which is not what we want in integ tests; besides, the case is covered by the CLI integ test. 

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*