Detect mixed versions of Sentry between Agent and normal dependencies

### Description

In previous work we intended to [crash the SDK on startup](https://github.com/getsentry/sentry-java/pull/4277) if mixed versions of Sentry are detected.

Right now this doesn't work in all cases, as is demonstrated here: https://github.com/lcian/sentry-samples-java/tree/main/mixed_versions_agent.

We should find a way to detect the mismatch and report it to the user, either by crashing the app or by finding another solution (e.g. reporting an issue in Sentry).