test(amazonq): Add e2e tests for /doc to cover different UX flow (#6631)

## Problem

## Solution
Add e2e tests to cover:
1. /doc update document flow.
2. Create document in a subfolder.
3. Cancel operation.
4. Discard or accept operation.

---

- Treat all work as PUBLIC. Private `feature/x` branches will not be
squash-merged at release time.
- Your code changes must meet the guidelines in
[CONTRIBUTING.md](https://github.com/aws/aws-toolkit-vscode/blob/master/CONTRIBUTING.md#guidelines).
- License: I confirm that my contribution is made under the terms of the
Apache 2.0 license.

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Co-authored-by: Avi Alpert <[email protected]>

Author: KevinDing1