Rename Dimension.role to Dimension.type

[Stiivi]

The "dimension role" has to be renamed to "dimension type" or something similar, as "role" has different meaning in the DW domain. If a dimension is associated with a cube multiple times, it acts in different role. For example: supplier and customer are two different roles of a dimension organisation, similar start date and end date are different roles of a dimension date.

Impact on Existing Code

This change is a breaking change and requires rewrite of models. We can wrap it temporarily by a deprecation warning.

[Stiivi]

Marked as bug as this is conceptual issue. Dimension role has well defined meaning in this context.