post apiv5 merge improvements
- instead of embedding BitmaskCoreMobile interface into BitmaskMobile, try to assign an empty BitmaskMobile struct to BitmaskCoreMobile typed variable in order to ensure on compile time that BitmaskMobile implements all methods of BitmaskCoreMobile
- fix missing error handling for GetStorage() calls in BitmaskMobile
- update go.mod and go.sum
closes #36 (closed)
follow-up of !36 (merged)