Copyable: Missing copyTo for Map-Field (from: anyAttribute)

Generating classes from XLIFF 1.2 (see https://docs.oasis-open.org/xliff/v1.2/cs02/xliff-core-1.2-strict.xsd) using the copyable plugin results in all classes missing a way to clone "otherAttributes" which are introduced by this XSD entry (see for example `trans-unit` element):

```xml

```

As workaround I manually added a corresponding section within the `copyTo` block (we only generate classes on demand). But of course in the long run this approach isn't feasible.

Did I miss any configuration option? As it seems not only the `copyable` plugin ignores this field (but there it is most harmful) but also the `equals`, `hashCode` and `toString` plugin.