Removed unused LinkTaskManagers

refs #5955

Removed code relating to deprecated taskTypes, including LinkTaskManagers
and database entries.
Remove normalization of submission documentation

refs #5955

Removed chain links to normalize submission documentation.  Submission docs
are usually text files not in need of normalization, and the normalization
fails if the files aren't identified, which they currently aren't.  Also,
cleanup of unused MicroServiceChainLinks.
Updated maildir normalization

refs #5955

Added the ability to filter subdirectory on a SIP basis, and used that to
filter by objects/attachments for Maildir in normalization and
identification.

Rather than make many separate MicroServiceChainLinks for Maildir
normalization, added a UnitVariable with the name of the script it applies
to, and a variableValue of {'filterSubDir':'directory to filter'}. The
LinkTaskManager for 'run on every file' checks to see if a UnitVariable for
this script and SIP exists to override filterSubDir, and applies it if one
exists.

The normalization report now only displays files that had a Task run for
them.