new feature request: deparse_pkg_ref()

[pawelru]

I want to be able to modify the remote_ref class of object and then deparse it for further use in pkgdepends or pak. As an example, I want to use a particular commit sha given the "foo/bar" string reference. I want to be able to do the following:

x <- parse_pkg_ref("foo/bar")
x$commitish <- "xyz"
x |> deparse_pkg_ref() |> pak()

I manage to find my way to do this (probably not perfect) but I thought it would be great to have it as apart of the package API.