Steps to reproduce (assumes ChromeVox or similar)

Long story short: All of these items need to trigger screen reader events when they change the content of the table they are connected to with, at the very least, the number of rows returned as a result of user action.

1. Open https://elastic.github.io/eui/#/display/tables in a new tab.
2. Tab to the inputs under the "In-Memory Table - Selection" heading.
3. Tab to the "Load Users" Button
4. Press enter

Actual Result

silence

Expected Result

"Search|Filter complete. 8 rows returned"

Category: #688: Elastic UI Tables Accessibility
Relevant WCAG Criteria: 3.2.2 Predictable: On Input