[RH-SSO 7.2] [RH-SSO 7.3 TP CD] Split os-sso module into version specific RH-SSO and common RH-SSO modules

The RH-SSO 7.2 for OpenShift and RH-SSO 7.3 TP CD for OpenShift images utilize os-sso72 and sso.config.launch.setup (former os-sso73) module, respectively:

• RH-SSO 7.2 version,
• RH-SSO 7.3 TP CD version which currently combines both:
• The part necessary for configuration and launch of some specific version of the RH-SSO product (e.g. standalone-openshift.xml and openshift-launch.sh scripts), with
• The part common to all RH-SSO images – not changing when the version of the underlying RH-SSO product changes (e.g. import-realm.json, index.html files, or majority of the files located under launch subdirectory).

Acceptance Criteria:
The change should split current os-sso72 module into two separate modules as follows:

• Keep the common (not changing across RH-SSO versions) part under os-sso-common module, and
• Place the RH-SSO version specific (changing part) into sso.config.launch.setup RH-SSO module.

This way the code duplicity (currently present) will be eliminated – if there's a bug common to all RH-SSO images, it will be enough to correct it in os-sso-common module (and not in each RH-SSO image version).