Windows: Refactor AFSParseName related name parsing

AFSParseName() is a very long complex function.  Extract the parsing
of RelatedFileObject name parsing to a new function AFSParseRelatedName().
This removed ~160 lines of source code out of AFSParseName().

This changeset is not intended to introduce any functional changes.

Reviewed-on: http://gerrit.openafs.org/11394
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>
(cherry picked from commit d57d87a87a6041b1596532c7fe08795ae9d91b95)

Change-Id: Ife845887bad302937b2bfc4242911332c59292b5
Reviewed-on: http://gerrit.openafs.org/11406
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>