Add the max total size of index / filter blocks for all cf-s sharing a block cache

[udi-speedb]

The "Block-Cache-Stats" Object shows the size of the largest index / filter block that was created for any cf sharing the same block cache in this DB instance.
The request is to find the max total size (and time point for that event) of all index / filter blocks of "live" files (files that were created but still not deleted). This value is also in the scope of all cf-s sharing the same block cache.