FR: Add option to specify log/report timerange as calendar week, month or year

[varac]

It would be lovely if watson could handle timerange shortcuts like i.e.

watson report --calweek 5  # shortcut for --from 2023-01-30 --to 2023-02-05
watson report --calmonth Jan  # shortcut for --from 2023-01-01 --to 2023-01-31
watson report --calyear 2022  # shortcut for --from 2022-01-01 --to 2022-12-31

where the cli option names are just example.