Local Application Testing

## Description

Short description of the proposed feature.

## Roles

| Role | User
|---------------------|------------------------------
| Proposed by | @alias
| Author(s) | @alias, @alias, @alias
| API Bar Raiser | @alias
| Stakeholders | @alias, @alias, @alias

> See [RFC Process](https://github.com/aws/aws-cdk-rfcs#rfc-process) for details

## Workflow

- [x] Tracking issue created (label: `status/proposed`)
- [ ] API bar raiser assigned (ping us at [#aws-cdk-rfcs](https://cdk-dev.slack.com/archives/C025ZFGMUCD) if needed)
- [ ] Kick off meeting
- [ ] RFC pull request submitted (label: `status/review`)
- [ ] Community reach out (via Slack and/or Twitter)
- [ ] API signed-off (label `status/api-approved` applied to pull request)
- [ ] Final comments period (label: `status/final-comments-period`)
- [ ] Approved and merged (label: `status/approved`)
- [ ] Execution plan submitted (label: `status/planning`)
- [ ] Plan approved and merged (label: `status/implementing`)
- [ ] Implementation complete (label: `status/done`)

---

> Author is responsible to progress the RFC according to this checklist, and
apply the relevant labels to this issue so that the RFC table in README gets
updated.

Start with the linked RFC Process and use this issue's checklist as the entry point. The issue currently contains only the RFC template, so first establish the proposed local application testing workflow and stakeholders before progressing the RFC stages. Done means the RFC is submitted, reviewed, approved, and its implementation plan and completion are recorded through the checklist.

Written by the indexing model from the issue text.