Post list tables row headers changed

The column used as the primary list table th with scope="row" was moved from the first column, containing the selection checkbox, to the second column, containing the post title and row actions in #32892.

This change significantly improves accessibility for post list tables by ensuring that the naming used for screen readers to identify the current row refers consistently to the name of the relevant post, rather than referring to a selection checkbox that may not be present if the post is not currently available for editing.

This is expected to have an impact on extenders who assign custom styles