[MDEP-793] ignoredUsedUndeclaredDependencies not affected to non-test scoped

**[Slawomir Jaranowski](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=slawekjaranowski)** opened **[MDEP-793](https://issues.apache.org/jira/browse/MDEP-793?redirect=false)** and commented

When we add some of artifacts to **`ignoredUsedUndeclaredDependencies`** and use classes from this artifacts only in test code we have reported it as  **`non-test scoped`**.

In order pass **`non-test scoped`** check we must add artifacts to project .... but we want to avoid adding according to **`ignoredUsedUndeclaredDependencies`**

Logs from executing:

```
[WARNING] Non-test scoped test only dependencies found:
[WARNING] joda-time:joda-time:jar:2.10:compile

[INFO] Ignored used undeclared dependencies:
[INFO] joda-time:joda-time:jar:2.10:compile
...
```

---
No further details from [MDEP-793](https://issues.apache.org/jira/browse/MDEP-793?redirect=false)

Reproduce the logged case using ignoredUsedUndeclaredDependencies with an artifact referenced only by test code, then inspect the dependency-plugin checks that report non-test scoped test-only dependencies. Done means an ignored artifact is not reported by that check while the existing dependency analysis continues to work.

Written by the indexing model from the issue text.