Cannot add field default value if it contains a collection of records

[ex-ratt]

When manually creating a record codec, then it is possible to define default values for fields. This works most of the time, but it will not work if the value is a collection or has a nested collection that contains records. See the following example to reproduce the issue:

import vulcan.Codec
import vulcan.generic.*

case class Element(value: String)
case class Collection(elements: List[Element])

implicit val elementCodec: Codec[Element] = Codec.derive
implicit val collectionCodec: Codec[Collection] = Codec.record(
  name = "Collection",
  namespace = "whatever",
)(field => field(name = "elements", access = _.elements, default = Some(List(Element("a")))).map(Collection.apply))

println(collectionCodec.schema) // Left(AvroError(org.apache.avro.AvroRuntimeException: Unknown datum class: class org.apache.avro.generic.GenericData$Record))

The bug is caused by a missing case in vulcan.internal.schema.adaptForSchema(Any). There is a recursion for IndexedRecord, but it would also need to recurse on the elements of java.util.Collection or java.util.List (the actual type of encoded is java.util.ArrayList according to the debugger).

If the field elements in the example above is Map[String, Element] instead of a List[Element], then the schema could also not be generated, because encoded would be a JavaCollectionWrappers.MapWrapper, which is also not handled.