[R] Rename read_ipc_file to read_arrow_file & highlight arrow over feather

Following up from [this mailing list conversation](https://lists.apache.org/thread/nxncph842h8tyovxp04hrzq4y35lq4xq), I am wondering if the R package should rename `read_ipc_file()` / write_ipc_file()` to `read_arrow_file()`/ `write_arrow_file()`, or add an additional alias for both. It might also be helpful to update the documentation so that users read "Write an Arrow file (formerly known as a Feather file)" rather than the current Feather-named first approach, assuming there is a community decision to coalesce around the name Arrow for the file format, and the project is moving on from the name Feather.

**Reporter**: [Stephanie Hazlitt](https://issues.apache.org/jira/browse/ARROW-18148) / @stephhazlitt

_{**Note**: *This issue was originally created as [ARROW-18148](https://issues.apache.org/jira/browse/ARROW-18148). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*}