feat: Add Contellation::put_many

[dariusc93]

The current api does not support multiple uploads so one would have to make multiple Constellation::put calls and poll each stream that is returned to completion. While one could get around this by polling the streams, either individually or collectively (since the progress does return a name that can be tracked), I do believe it might be more optimal to support an api that would do this internally while the end user would only have one stream to poll.

Note:

• There may be a limit to how many can be uploaded at one given time in warp-ipfs. While this "upload" is nothing more than storing it on the local node, we do not want to have a overwhelming number of files being stored at one given time, especially if a protocol is introduced to broadcast blocks or files out, or if the system storage is not the best. While we could batch these into separate task once it reach a threshold, I do feel that may not be desirable long term. Furthermore, when it comes to pinning these files on shuttle or some other service (if any), we dont want to have a overwhelming amount of data that may take a long time to pin either.