[R] Implement lubridate's parsers with year, month and date components

[asfimport]

Parse dates with year, month, and day components:
ymd() ydm() mdy() myd() dmy() dym()

Reporter: Dragoș Moldovan-Grünfeld / @dragosmg
Assignee: Dragoș Moldovan-Grünfeld / @dragosmg

Related issues:

• [R] Implement lubridate's individual date/time parsers (is a child of)

PRs and other links:

• GitHub Pull Request #13118

_{Note: This issue was originally created as ARROW-16394. Please see the migration documentation for further details.}

[asfimport]

Nicola Crane / @thisisnic:
Issue resolved by pull request 13118
#13118