Ability to list the ChannelManifest and Streams present in a ChannelSession

[jfdenise]

The current ChannelSession API lakes the ability to discover streams located in manifests. We need the following method:

public List<ChannelManifest> getManifests();

Allowing then to navigate to the Streams, for example:

for (ChannelManifest manifest : session.getManifests()) {
  for (Stream stream : manifest.getStreams()) {
...

[spyrkob]

@jfdenise I'm not sure on the use case, but the channel session can resolve artifacts not listed in the streams (via resolve-if-no-stream), so if the goal is to list artifacts that can be resolved, this might not be enough

[jfdenise]

@spyrkob , the goal is to get the streams that are configured in the set of channel manifests. No dynamic resolution is needed.