Check plugin compatibility during startup for stock plugins

## What?

The Graylog server should do a sanity check for the stock plugins shipped with it (and enterprise) to find out if they are compatible. If not, startup should be aborted.

## Why?

If e.g. Graylog server v4.x is started with v3.x stock plugins, startup will abort with a cryptic error message. Instead, the user should know what the issue is.

## Your Environment

* Graylog Version:
* Elasticsearch Version:
* MongoDB Version:
* Operating System:
* Browser version: