Original plan was to leverage Canvas notifications, but after some discussions with @8ballsteve , @amangrover90 and @ravi.maniyar.123 we've come to conclusion that purely client side toast messages that look similar to Canvas notifications, but aren't is a better fit at this time. MvP requirements for toast messages are: * Displayed on `HTTP 409` with errors containing items with code 4 from `HTTP GET` to `/auto-saves/pending` endpoint * Once displayed, we should store information required to make sure the toast notification is not being spammed on each `HTTP 409` response * Once dismissed, it should not be displayed again, unless the content of the conflict response changes Nice to haves: * An ability to do the same when `HTTP 409` response returned for the `HTTP POST` call to publish auto-save items (!1193) or `HTTP PATCH` to resolve a conflict (!1194) * Clicking on the link in notification should transition the user to the Conflict resolution UI (first item in the pagination) without a page reload - the SPA behaviour as per other Canvas UI * modifying the content of `‘Activity Center’` to show the ‘Cxonflict detected’ section (probably should use same copy as the selective publishing CTA) that looks like so: {width=453 height=600} {width=468 height=141}