[R] Make FeatherReader print method more informative

[asfimport]

Currently the print method for FeatherReader objects only prints the class name. Improve it so that it prints useful metadata similar to what read_feather(as_data_frame = FALSE) prints.

Reporter: Ian Cook / @ianmcook
Assignee: Jonathan Keane / @jonkeane

PRs and other links:

• GitHub Pull Request #9928

_{Note: This issue was originally created as ARROW-11906. Please see the migration documentation for further details.}

[asfimport]

Jonathan Keane / @jonkeane:
This should be similar to https://github.com/apache/arrow/pull/9171/files where a print method was added to SubTreeFileSystem

[asfimport]

Neal Richardson / @nealrichardson:
arrow/ipc/feather.h is where the Reader class is defined. Looks like there is a schema method you can use to print names and types (and the existing R column_names method could be rewritten to be names(reader$schema).

[asfimport]

Neal Richardson / @nealrichardson:
Issue resolved by pull request 9928
#9928