[MNG-7958] Confusing error message on required parameter

**[Christoph Läubrich](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=laeubi)** opened **[MNG-7958](https://issues.apache.org/jira/browse/MNG-7958?redirect=false)** and commented

If a required parameter is missing one gets the following error:

```java
The parameters 'repositories' for goal org.eclipse.tycho:tycho-eclipse-plugin:5.0.0-SNAPSHOT:eclipse-run are missing or invalid
```

This is very bad from user-experience point of view, there should be no doubt for the user if it is required (and missing) or invalid (present but has wrong value). If it is invalid it should even mention why (e.g. incompatible types).

---
No further details from [MNG-7958](https://issues.apache.org/jira/browse/MNG-7958?redirect=false)