Internal function - Builds inner breakdowns from nested report structure
BuildInnerBreakdownsRecursively(parent.element, elements, metrics,
current.recursion.level, context, accumulator = data.frame(),
date.range = "")element containing breakdown rows
list of all elements included in the report
list of all metrics included in the report
current recursion level, initial call should set this to 0, this increments as the function is called recursively
initially a blank list, with additional context added as we go further down the data structure
data frame used to accumulate the report data (yes, I use some for loops here, if anyone can find a better way to do this with hierarchical data, please submit a pull request)
date range for the report, these columns are added if specified
Flat data frame containing all key report data