[FEATURE] sap.m.SemanticPage: Added backgroundDesign property.
[FEATURE] sap.m.SemanticPage: Added backgroundDesign property.

Change-Id: I7b46a80bdbba7fc5a1a2cef47e6199664d9afe87

cschuff/openui5,nzamani/openui5,SQCLabs/openui5,cschuff/openui5,cschuff/openui5,SAP/openui5,SQCLabs/openui5,nzamani/openui5,SAP/openui5,SQCLabs/openui5,nzamani/openui5,SAP/openui5,SAP/openui5