Allow MXBean in IdentifierName

Naming an interface with the suffix `MXBean` marks it as being an [MXBean](https://docs.oracle.com/en/java/javase/17/docs/api/java.management/javax/management/MXBean.html). This should be allowed by the `IdentifierName` check such that one does not have to add a suppression to every MXBean interface.

There is also an `@MXBean` annotation that can be used as an alternative for the name suffix, but MXBeans are basically always a public API (they can be accessed via the JVM management interface), so probably many users will not want to rename existing types.