Remove Lit specific packages from `packages/core`

[pascalwilbrink]

@openscd/core should be framework agnostic. That's why any lit specific packages should be removed. (Including the translation).

Acceptance criteria

• [ ] dependencies list of packages/core should be empty.
• [ ] Mixins are removed from core
• [ ] Rollup is removed from core
• [ ] Web-dev runner is not part of core
• [ ] Web-test runner is not part of core
• [ ] LitConstructor is removed from foundation
• [ ] Translation is removed