Addresses bugs in 800-53 catalog (issues 224 226 227 for OSCAL conten…

…t patch 1.2.1 (#228)

* addressed issue 226: error in IA-13(03)

* addresses issue 227 by removing extra related links in IA-13(01)(02)(03)

* addresses issue 229 by using consistent structure for the IA-13 ODP params

* updated metadata and backmater to include a link to the CPRT SP800-53v5.1.1 resource

* addresses issue 224 by replacing labels with alt-identifies and adding leading zeros to accurately reflect the SP800-53 v5.1.1 release.

* updated root uuid, last-modified, revision history and back-matter.

* added leading zero to PM-7, PM-8 and PM-9 which were missing.

* fix the errors identified during the Schematron validation

* updated one more time the last modified and the uuid

* Updating Schematron rules in view of ongoing changes. (#230)

---------

Co-authored-by: Iorga <miorga@pn129618.campus.nist.gov>
Co-authored-by: Wendell Piez <wendell.piez@nist.gov>