Add `isProbablyUsingAdBlock()`

[lforst]

Description

For the pages injected by the wizard it would be great to have a function that detects whether the user is using an ad blocker so we can tell them to disable the adblocker to try out Sentry.

[github-actions]

A PR closing this issue has just been released 🚀

This issue was referenced by PR #15821, which was included in the 9.10.0 release.