LP1825851 Server managed/processed print templates

LP1825851 Server managed/processed print templates

Adds a new database table config.print_template (and IDL class) for
storing configurable, org- and locale-specific print templates.

Adds a web service which accepts POSTed print data and generates a
print-ready document.  Includes example Apache configs.

Teaches the Angular app to use the new web service for generting
print output.

Adds and Angular print template administration interface.

Adds HTML::Defang for scrubbing unwanted HTML elements and attributes
from print documents for security.

Add the new ADMIN_PRINT_TEMPLATE permission to the Circ Admin group at
System level as a default.

Adds 2 templates, a simple patron_address tepmlate (pending Angular port
of patron UIs) and a 'Holds for Bib Record' template, accessible from
the Angular staff catalog Holds interface.

Signed-off-by: Bill Erickson <berickxx@gmail.com>