Refactor HistoricalData#max_historical_user_count
In a review comment for fixing the incorrect seat overage calculation, a suggestion to refactor the method HistoricalData#max_historical_user_count
came up.
All calls for the method without parameters were removed so they can be made compulsory. Since this will remove the fallback logic within the method the license
parameter can be removed as well. The fallback logic was also closely related to license anyway and should be done within the License
model.