arrow

ARROW-14808 [R] Implement bindings for `lubridate::date()`

The following will be supported in arrow (`base::as.Date()` included to show the difference to `date()`, but not supported):
``` r
library(dplyr)
library(lubridate)

df <- tibble(a = as.POSIXct("2012-03-26 23:12:13", tz = "America/New_York"))

df %>%
  mutate(
    a_date = date(a),
    a_date_base = as.Date(a))
#> # A tibble: 1 × 3
#>   a                   a_date     a_date_base
#>   <dttm>              <date>     <date>
#> 1 2012-03-26 23:12:13 2012-03-26 2012-03-27
```

``` r
library(arrow)
library(dplyr)
library(lubridate)

df <- tibble(a = as.POSIXct("2012-03-26 23:12:13", tz = "America/New_York"))
df %>%
  arrow_table() %>%
  mutate(
    a_date = date(a)
  ) %>%
  collect()
#> # A tibble: 1 × 2
#>   a                   a_date
#>   <dttm>              <date>
#> 1 2012-03-26 23:12:13 2012-03-26
```

<sup>Created on 2022-02-15 by the [reprex package](https://reprex.tidyverse.org) (v2.0.1)</sup>

Closes #12433 from dragosmg/lubridate_date

Authored-by: Dragoș Moldovan-Grünfeld <dragos.mold@gmail.com>
Signed-off-by: Jonathan Keane <jkeane@gmail.com>