Rework axis cell resolution #76

Due to the historical reasons MDX2JSON uses naive axis cell resolution strategy which involves iterating all cells in the axis/tuple and determining their visibility later on.

This is implemented in a MDX2JSON.ResultSet class, specifically:

• AxesToListOfObjects - entrypoint
• ProcessOneAxis
• ProcessOneAxisCell - main work happens here

Compared to that, DSR uses a much more effective approach of using %GetOrdinalLabel (see %ZEN.Auxiliary.jsonMDXProvider:%DrawJSON).

We need to move to this approach - it's faster and would prevent the whole visibility debacle.

Related hotfix.