Deleted the checking of the presence of non superseded files during an Archive Mount.

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

Added a check while mounting a tape for writing : if some tape files located in the writing tape are not superseded by others,
the write session will fail.

Note: The test CatalogueTest.exist_non_superseded_files_after_fseq is supposed to fail.

Harmonized the copyNb type to uint32_t
Corrected a bug in RetrieveQueue::getContainerSummary() --> After insertion in the queue, the number of files and bytes added were equal to 0.

Added the first version of the specification of the Catalogue::getTapeFilesForRepack() method - there's no implementation yet

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

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

The catalogue can receive polymorphic items as input for recording.
The strict sequencing of fSeqs is still enforced.
Currently, 2 items types are recorded: files and placehoders.
Files are recorded to the tape catalogue, while place holders are not,
but they are used to enforce the fSeq sequencing.

Done

This reverts commit 5ac9086c.

The CI was incorrectly failing.  There was nothing wrong with
the original commit that made the Catalogue class a pure
interface.

This reverts commit e07bb359.

RdbmsCatalogue::getTapesForWriting() should re-connect to database if connection lost.

Revert "cta/CTA#186 CTA should cope with idle database connections being dropped by the database server"

This reverts commit 1587c5b6.

Refactored RdbmsCatalogue::getTapesForWriting() to be like OracleCatalogue::filesWrittenToTape()

Moved TapePool from common::dataStructures:: to catalogue:: because it belongs to the Catalogue interface

This commit does two things.  Firstly it puts back the call from:

    XrdCtaFile::xCom_deletearchive()

to:

    Scheduler::deleteArchive()

Secondly it moves the reponsibility of logging the
"Archive File Deleted" message from the CTA front-end (XrdCtaFile)
to the CTA catalogue.

Please note that Scheduler::deleteArchive() still does not call
SchedulerDatabase::deleteArchiveRequest().