a11y: Improve HTML table in PHUIFormationView
Summary:
Ideally this would not be a "layout table" at all but for now, improve accessibility by
* marking the table in `PHUIFormationView` as a non-data table via `role="presentation"` so most screenreader software will not output the table skeleton parts; see https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Reference/Roles/presentation_role
* explicitly setting `aria-hidden="true"` on the `PHUIFormationResizerView` visual slider to completely hide it from screenreader software.
Closes T16195
Test Plan: Go to http://phorge.localhost/D1, inspect the HTML table parameters. Or try some screenreader software on it and realize a small improvement.
Reviewers: O1 Blessed Committers, valerio.bozzolan
Reviewed By: O1 Blessed Committers, valerio.bozzolan
Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno
Maniphest Tasks: T16195
Differential Revision: https://we.phorge.it/D26221