Add default folder for S3 connector into Configuration

[zdenek-jonas]

Based on customer needs, we should consider adding a specific configuration key to enable storing data in a designated folder in S3. Currently, the data is stored directly in the root. Changing this behavior in Spring, for example, means that the user cannot utilize the auto-configuration framework and must create everything manually, which is not convenient.

Tasks:

• Add a configuration key to the S3 connector
• Include this key in the Spring configuration

Issue based on discussion:
#196

[fschon]

Do you mean a "designated folder" or a "designated bucket" or both? I would prefer to have a configuration for both. That way I can use the same bucket with its backup capabilities for multiple data stores.