Extend livesync tests for HMR (and not only) #199

@radeva gathered some specs on what we should cover in livesync tests.
Items are listed in context of testing HRM, but I believe we should also have the same without HRM/bundle.

Note some of the cases below might lead to app-restart. However, having test that assure that changes are visible (event after restart) is essential.

Angular

• Changes in component code
• Changes in component code in lazy modules
• Changes in global CSS (app.css)
• Changes in component CSS

Vanilla TS/JS

• Changes in JS/TS
• Changes in page XML
• Changes global CSS
• Changes in page CSS

Eventually same for Vue.