775 account page notifications

[ekraffmiller]

What this PR does / why we need it:

Implements the Notifications tab of the Account Page.

Which issue(s) this PR closes:

• Closes Account Page: Notifications - UI Integration #775

Special notes for your reviewer:

This implementation uses a NotificationContext, and polling to get notification updates. I didn't add the icons next to the messages because I don't think they add much value, but if it's wanted I can add them.

Note that a

Suggestions on how to test this:

Do some actions in the SPA to trigger notifications. For example, create a new account, publish a dataset, upload a .csv file, or assign a role. The actions should update the Header to show the new unread notifications. Go to the Notifications tab to view them.

Note that a follow up PR will introduce paging, so that will handle the performance issues currently seen in JSF when there is a large amount of notifications.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Yes, rather than showing new notifications highlighted until the page is refreshed, as done in JSF, the SPA version of the page removes the highlight of the new notifications after a 2 second delay. After two seconds, the new notifications are marked as read, and the highlights are removed, and also the unread notifications badge is removed from the Header.

JSF Version

SPA Version

Is there a release notes update needed for this change?:

Additional documentation:

[coveralls]

coverage: 98.249% (+0.4%) from 97.83%
when pulling 7493817 on 775-account-page-notifications
into 212fa23 on develop.