retain interfactor correlation matrix directly from rotation procedures

[maxheld83]

currently, we seem to be calculating the interfactor corr matrix results$f_char after the fact, though most rotation procedures give you these right away.

Maybe that's something too look into?

Related: I recall that someone on the Q list pointed out that interfactor corr matrix with weighting/flagging/ etc doesn't really make a lot of sense as per -> #29

So maybe we'd rather report this here.