Packages do not specify an `exports` field

Packages in the workspaces should set the exports field in the package.json file. As Node.JS doesn't read the module field, the ESM output may be skipped if the exports field is not added.

Specifying the exports field also prevents modules that are written in ESM from being interpreted as CommmonJS. For example, it is currently possible to make the following import:

import foo from "@patternfly/react-drag-drop/dist/esm/next/components/DragDrop/DragButton"

Since there is no type specified this file would be considered CommonJS, even though the source is actually written in ESM.

The exports field supplants the main and module fields, which should be removed when the exports field is introduced. This would be considered a breaking change.

This is part of a series of issues resulting from publication linting introduced under #10764

workspace の package.json ファイルと、#10764 の公開用 linting のコンテキストを確認します。パッケージに exports エントリを追加し、該当する場合は不要になった main フィールドと module フィールドを削除して、ドキュメント化された ESM import が Node.js によって正しく解決されることを検証します。