recalculate frag % based on compaction.min_size

For Index fragmentation based on % happens, where fdb file size is compared with value - compaction.min_size. If fdb file size < compaction.min_size, there is no compaction happening.

Once fdb file size > compaction.min_size, then based on the % full compaction would happen.

This will be true when file size has reached compaction.min_size.
But if the index file is < compaction.min_size, user will be shown wrong information on UI, the compaction on smaller fdb files will be higher than what is set on settings, but user will not see any compaction occurring.

I believe we should recalculate information that we show on the UI for accuracy, else use will be confused.