Simplify handling of different data cubes

[OldLipe]

Describe the requested improvement Allow information from data providers to be included dynamically when creating a data cube. This improvement avoids the need to increase the information available in the configuration files. To do this a new column (cube_info) will be included in the sits_cube() data structure.

Associated sits API function sits_cube()

[rolfsimoes]

To support both current version and this feature, all access to the config must be done by .cube_conf_*() API that resolve for .conf_*() API calls.