Feat: Move to Playwright

[pascalwilbrink]

Web-Test-Runner is making use of a specific lit version. If we want to upgrade Lit, we also need to change WTR.
In order to have this split, we need to migrate to a different testing framework.
One of the Frameworks that natively supports Custom WebComponents, is Playwright.

The following packages need to start using playwright:
@openscd/open-scd
@openscd/components
@openscd/plugins
@openscd/addons