Add an aselo webchat E2E test

[stephenhand]

Description

We are migrating from the legacy webchat client defined in the webchat directory to a new version defined in the aselo-webchat-react-app directory

We need an E2E test similar to the existing 'webchat' test, but using the new client rather than the legacy one.

You need to

• Add a new test that follows the same flow as the existing webchat test, but for the new client
• Add a set of parallel POM support code for the new client
• The new test will need to complete the pre-engagement form

Additional context

The aselo-webchat-react-app client is deployed to https://assets-development.tl.techmatters.org/aselo-webchat-react-app/e2e/