band to tridiagonal scaling improvement: First attemp#1018

Draft

rasolca wants to merge 2 commits intomasterfrom

rasolca/band_to_trid/distr

Commits on Oct 25, 2023

First attempt: duplicate work on each column, HHR communication happens only in the column
rasolca
committed
Avoid storing HHR which are not used by the column.
rasolca
committed