These commands are not implemented so I have removed them from the cta-admin
interface.

Fixes race condition: for text stream responses, guarantees that
header is printed before the stream data.

Simple repack on CI

Replaced the map of tape files with a list as the assumption that we have one copy per copyNb is no more valid with repack.

cta-admin was failing due to incoherent internal data.

Added MEDIA_TYPE and VENDOR columns to TAPE table and upgraded xrootd-ssi-protobuf-interface to v0.29

Usage: cta-admin --json <command> <subcommand> <options>

For stream commands only (where each line of the result is sent back in
a protocol buffer), return the results in JSON format instead of a
text table.

Adds better cleanup of Requests. The Send() method is synchronous as
before, for Metadata requests. The new SendAsync() method is for Data
and Stream requests, where the Response is returned asynchronously.

The framework now provides a DataFuture object for the asynch case.
After the Request has been sent, call DataFuture::wait() to clean up the
Request object once all data has been received.

Added partial support for repack queueing in scheduler database,
scheduler and CLI.

This reverts commit 5cda9ec6.