[GNC] Proposed change of "U+R" and "R" in the Import main matcher.

[Patrick]

> The csv import can import reconciliation info so in principle you could
import
reconciled transactions.

Sorry for the somewhat tangential comment, but since it is I think somewhat
relevant, and I thought it might be of interest to someone - when importing
transactions from a csv, GnuCash didn't seem to allow the first split in a
multi-split transaction to import as anything other than the "c" (cleared)
state, regardless of what the csv contents were. I ended up modifying the
source code to allow this, but maybe it is possible another way, and I just
couldn't find it. The bug linked below suggested to me that there might not
be a way.

References
https://bugs.gnucash.org/show_bug.cgi?id=796890
https://lists.gnucash.org/pipermail/gnucash-user/2019-July/085876.html