ENH: Add support for visual totals to Dynamic Cubes

In a hierarchy with multiple levels (say Region and Country for example) if a user only has security granted for certain countries when Region is pulled into the report there are a couple ways the aggregates could be shown.

Dynamic Cubes by design will show either the total value (rolling up the values for countries that the user does not have access to) or ""--"" depending on whether ancestor access is granted in the security filter. This allows for more widespread caching and reuse since the value of the parent tuple is the same across different security profiles and can be shared and reused by different users and such it is the only aggregation Dynamic Cube currently supports.

Some customer would rather see ""visual totals"" where the value for the parent region would instead show the sum of only those countries which the user is granted access to. This results in a more intuitive report output in some cases (especially if both Country and Region are included in the same report) but prevents widespread tuple reuse since different values must be stored for users with different security profiles needing us to either go back to the database or cache a lot more tuples in memory.

While it may not be appropriate for all (or even most) use cases there are customers whose data volumes may not be so large that the extra memory use or database hits prevent visual totals from being viable. Or there may be scenarios where there are only a few different security profiles so reuse within the profiles would still be pretty widespread. In these type of scenarios it would be beneficial for clients to be able to enable visual totals at the cube level to allow for more intuitive rollups in their reporting. Perhaps implementing as an advanced setting so that it won't be casually turned on by clients who don't realize the impact it will have on the system.