Added flexible HANA provisioning capability

[rhmk]

I have changed the internal internal only variable hana_source_path to sap_hana_installdir. When the variable sap_hana_installdir is defined and the variables for the sar bundle are undefined the role now skips the unpacking block. So it stays fully backwardscompatible with previous functionality If sap_hana_installdir is defined , the role checks if hdblcm exists in this directory, otherwise it stops with an error. Now sap-hana-mediacheck can be used to mount or unpack hana archives from any location in the network.

[rhmk]

By introducing the variable sap_hana_deployment_hdblcm_extraargs I have added an additional feature. With this newly defined variable you can pass additional parameters to hdblcm. This is useful for testing on "unsupported" platforms.

[makentenza]

@rhmk just tested your changes, please review my notes. Also, on the sap_hana_deployment_hdblcm_extraargs and the ability to run this in "unsupported" platforms, I think we need to discuss this further as the long term goal is to move this Role as part of the supported System Roles for SAP, and adding 'not supported' scenarios is something Engineering supporting this role would potentially don't like

[makentenza]

Tested and validated. LGTM