LP#1427287: methods to retrieve entire tag table

LP#1427287: methods to retrieve entire tag table

This patch adds methods to open-ils.cat for
retrieving either the entire tag table or just the list
of MARC fields, either from the stock MARC format
seed definition or as potentially customized for the user's
workstation OU:

open-ils.cat.tag_table.all.retrieve.stock
open-ils.cat.tag_table.all.retrieve.local
open-ils.cat.tag_table.field_list.retrieve.stock
open-ils.cat.tag_table.field_list.retrieve.local

The user must have UPDATE_MARC permission.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>