Watch mode improvements for browser runner

[christian-bromann]

Proposed changes

It turns out that there is a race condition when Mocha tries to start the test without the worker process being ready and initialised. This patch is an attempt to fix that.

fixes #9612
fixes #9608

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
• I have added proper type definitions for new commands (if appropriate)

Further comments

Missing for this to land:

• find a better approach to auto trigger or wait for the browser runner: if we let the browser runner trigger the framework to start, we loose the ability to re-run tests through hot reload (e.g. due to changes to the component)
• let's add smoke tests to ensure we test watch capabilities created new issue for it: [🐛 Bug]: Add smoke tests for watch mode #9974

Reviewers: @webdriverio/project-committers