Subset of tickets in #614 that deal with the "Toasts" category of EUI, anything that falls on or under this URL: https://elastic.github.io/eui/#/guidelines/toasts

• Toast Messages Should Be Read by the Screen Reader on Display Toast Messages Should Be Read by the Screen Reader on Display #715
• Toasts should remain open long enough for the screen reader to read them Toasts should remain open long enough for the screen reader to read them #716
• Allow the toast time limit to be paused when a toast element is focused, not just on mouseover Allow the toast time limit to be paused when a toast element is focused, not just on mouseover #717
• Use patterns or icons in addition to colors to signify toast types Use patterns or icons in addition to colors to signify toast types #718