This patch adds a `--latest` option to limit snapshots list to the n
last snapshots. It is very similar to the `--last` one but does not
limit to one entry. It also deprecates the `--last` flag usage in
favor of `--latest 1`
Output example:
$ restic snapshots --latest 2
repository 0d3eb989 opened successfully, password is correct
ID Time Host Tags Paths
------------------------------------------------------------
5a33bdcc 2020-12-14 12:30:00 local /home
73887d8e 2020-12-15 12:30:00 local /home
------------------------------------------------------------
2 snapshots
Signed-off-by: Sébastien Gross <seb•ɑƬ•chezwam•ɖɵʈ•org>
