[R] Feather reader/writer should accept a MemoryPool

[asfimport]

#8533 (comment)

Currently feather readers and writers will allocate all buffers from the default memory pool. This is contrary to the Arrow convention of allowing control over memory allocation.

Reporter: Ben Kietzman / @bkietz
Assignee: David Li / @lidavidm

PRs and other links:

• GitHub Pull Request #9939

_{Note: This issue was originally created as ARROW-10421. Please see the migration documentation for further details.}

[asfimport]

David Li / @lidavidm:
Looks like it's available in Ipc{Read,Write}Options/IOContext and just needs to be hooked up.

[asfimport]

Ben Kietzman / @bkietz:
Issue resolved by pull request 9939
#9939