Adjustments for ember-v2 branch

[mydea]

This PR adds some adjustments to the getsentry#19229 PR branch:

1. Run yarn fix at repo root to ensure consistent formatting
2. Streamline stuff a bit, esp. around timing and the browser tracing integration. There were some quirks there apparently with the setTimeout approach in a strict resolver app. This PR changes the behavior to always start the pageload span immediately, even if no router/location is available yet, and simply updates this when it gets the data later. this is more aligned with other SDKs as well and should be safer too, it seems to work in all ember test apps.
3. Add a ember-strict-resolver test app and remove the demo app from the ember package itself.
4. fix the ember-vite test app
5. Add a instrumentEmberAppPerformance export as core utility to use
6. Removed loads of dependencies we no longer need for the core ember package

[mydea]

no idea if there is another way to make this work, couldn't find any docs or examples around this, but this seems to work...