fix: first and last week of month and year

[scroskey-clinc]

Fixes Time rules for the first/last week of a month/year. Previously, these rules would return the gregorian definition of first/last which in some cases excludes the first or last day of the month/year.

Examples:

• the first week of 2020
• the second to last week of july
• last monday of 2021
• last week of october
• the week of october 6th

[RajanMehtaClinc]

I've validated all the rules and they work as expected.

Just one exception:
week of october 6th doesn't work.
the week of october 6th works fine.

Approving the PR as it is safe to backlog the above issue