Clash in naming convention between OGS and ogstools

There is quite big difference between what "properties" are in OGS and ogstools.

In OGS they are physical properties describing simulated medium (prj-file->media->medium->properties). In this context name propertylib may suggest functionalities which are in scope of ogs6py.

In ogstools they refer to output variables, which in OGS prj-file would be process-variables and secondary-variables.

Better naming scheme is required to avoid confusing users.

Proposed solution: rename propertylib to reflect its scope correctly: results_presets, outputvarlib, ...