[internal] Reducing the cc size

[JanMarvin]

I was thinking about cc and it's size. Part of the issue is that we create 4 or 5 columns for formulas whenever we create cc unrelated to the question if formulas are part of the worksheet. This is delaying the loading time of smaller packages a few microseconds and of course cumulates for larger workbooks.

I haven't touched the code yet, because I learned time and time again, that my gut feeling what is improving speed is not related to reality and working on things often was just a very time intensive waste of my scarce free time. And on top of this, I've built this package around cc and touching it feels a bit like an open heart surgery.

Anyhow, to get the thought out of my brain. We could separate all formula related columns in a different data frame (ff). This can be a subset of cc only for cells with formulas. When required, we can merge both data frames to create the larger cc data frame.