[Chapel Merge] Deprecate ItemWriter and no-doc ItemReader

Branch: refs/heads/main
Revision: 3c04dfc
Author: benharsh
Link: Unavailable
Log Message:

Merge pull request #19829 from benharsh/hide-channel-item

Deprecate ItemWriter and no-doc ItemReader

Resolves #19318

This PR deprecates the ItemWriter type because it is not used anywhere except for a single dedicated test (that this PR moves under the deprecated directory).

This PR also hides the implementation detail that is ItemReader in documentation.

[reviewed by @lydia-duncan]

Modified Files:
A test/deprecated/IO/itemWriter.chpl

A test/deprecated/IO/itemWriter.good
R test/io/bradc/itemWriter.chpl
R test/io/bradc/itemWriter.good
M modules/standard/IO.chpl

Compare: https://github.com/chapel-lang/chapel/compare/9fe66a80d82a...3c04dfc0a270