Additional e2e tests for up down arrow navigation

[francescoopiccoli]

Problem

Add e2e test coverage for up/down arrow navigation, testing scenarios where the prompt is not sent, and when there is a code attachment inside the prompt.
We also rename some old tests for consistency with test naming.

Tests

• I have tested this change on VSCode
• I have tested this change on JetBrains

License

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

[natdurlik]

From my local testing, it looks like the "Prompt navigation" tests are being affected by the "should parse markdown" test. In the markdown tests, we update the viewport size of the page using page.setViewportSize. The Failing screenshots can be reproduced by adding an "only" mark to these two test suites.

This could be fixed by having a setup that resets the page viewport after each test. For example adding await page.setViewportSize(DEFAULT_VIEWPORT); in the beforeEach clause to ensure a consistent viewport size across tests. (This also cloud be fixed by changing the order of tests in source code, so that the markdown tests are the last in the file, but it's not the right solution.)