remote: checkout: save checksums without re-computation
remote: checkout: save checksums without re-computation

We do a similar thing on save, where we set cache checksum from already
computated ones for actual data. This patch does the same thing but in
revers: on checkout we know cache checksums, so we can set data
checksums from it without having to re-calculate it.

Fixes #1991

Signed-off-by: Ruslan Kuprieiev <e9bfb2c543dd33934bcff71879b108246996b567@iterative.ai>

dmpetrov/dataversioncontrol,efiop/dvc,efiop/dvc,dmpetrov/dataversioncontrol