* Renamed interpolation tests files to use the same naming as the source files
* Fixed in the mean time revealed bug of the interpolation tests, that did not clear caches after changing the visible state of datums (the groupBy was previously done on a linked partData that now is spared of being created in some cases; there was no cache on the root level before).
* Fixed global leak in the number format tests, that left the global groupSizes changed, and affected other unrelated tests.
* Simplified a Dimension unit test