Currently when aggregating reports over multi periods, we get the blob data for every child period, inflate the blob data for every period into a DataTable tree, then add them together. Afterwards we clean up the extra DataTables, but in the meantime a lot of memory is used, especially when the reports are large. This PR switches to inflating the DataTable tree for just one period at a time and should use less memory overall.
Transitions screenshot change is not correct, but it is due to an unrelated bug: https://github.com/matomo-org/matomo/issues/17875
Looks good to me @diosmosis 👍 Great, this will reduce memory quite a bit 💯