Merge styles and utils

[MarcusNotheis]

The styles and the utils package are requiring each other, so we duplicate code inside at the moment. Moving forward we want to use the styles from the ui5-webcomponents, so there is no need to keep those packages separate.
--> Merge the styles and the utils package into a new package base.

ToDos:

• Move Packages into new package base
• Adjust Readme
• Adjust npm release scripts
• Deprecate styles and utils on npm
• Delete old styles sap_belize, sap_belize_plus and sap_belize_hcb