arrow

ARROW-15092: [R] Support create_package_with_all_dependencies() on non-linux systems

This PR aims to address ARROW-15092 and ARROW-15608, allowing the function `create_package_with_all_dependencies()` to be run on non-linux systems.

To accomplish this, the code parses the [versions.txt](https://github.com/apache/arrow/blob/master/cpp/thirdparty/versions.txt) file in R. This process is a little hairy, because the existing code in versions.txt and [download_dependencies.sh](https://github.com/apache/arrow/blob/master/cpp/thirdparty/download_dependencies.sh) depend on shell substitution and array parsing.

In writing this PR, I assumed that only base R functions were available, and the format of versions.txt couldn't be changed to make things easier. I wrote some roxygen-like documentation, but didn't actually want to generate the `*.Rd` files, so just started the lines with `#` instead of `#'`.

I'd be very grateful for feedback here. The first question is whether this approach makes sense at a macro level, and then whether my implementation seems reasonable.

Closes #12849 from karldw/fix-15092

Authored-by: karldw <karldw@users.noreply.github.com>
Signed-off-by: Jonathan Keane <jkeane@gmail.com>