XWIKI-21776: Admin section: make the Notifications section pass webstandard tests

[Sereza7]

Jira URL

https://jira.xwiki.org/browse/XWIKI-21776

Changes

Description

• Added a fallback for null value of $divData
• Added a label for the id="since" input at the end of the form
• Added a missing space between attributes in email preferences
• Replaced the comment with an actual test for Notifications

Screenshots & Video

No visual change.

Executed Tests

• Successfully passed mvn clean install -f xwiki-platform-distribution/xwiki-platform-distribution-flavor/xwiki-platform-distribution-flavor-test/xwiki-platform-distribution-flavor-test-webstandards -Dxwiki.test.startXWiki=false after updating the live distribution with the changes in this PR.

Expected merging strategy

• Prefers squash: Yes
• Merge only on master.

[surli]

Could you run xwiki-platform-notification-test-docker with your changes here?

[Sereza7]

After updating my builds of the changes with mvn clean install -f xwiki-platform-core/xwiki-platform-legacy/xwiki-platform-legacy-events-hibernate/xwiki-platform-legacy-events-hibernate-ui and mvn clean install -f xwiki-platform-core/xwiki-platform-notifications/xwiki-platform-notifications-ui, I launched the build mvn clean install -amd -f xwiki-platform-core/xwiki-platform-notifications/xwiki-platform-notifications-test -pl :xwiki-platform-notifications-test-docker -Pquality,integration-tests,docker. It had one failure, on AllIT$NestedNotificationsEmailsIT. IMO this failure is not related to the changes in this PR. Here is a paste of the failsafe logs.

[Sereza7]

I can't reproduce this fail on master. Need to fix it before merging.

[Sereza7]

Okay, it seems it was a fluke. After further analysis, it didn't seem like my changes were related to the error.
I reran the whole command: mvn clean install -f xwiki-platform-core/xwiki-platform-legacy/xwiki-platform-legacy-events-hibernate/xwiki-platform-legacy-events-hibernate-ui; mvn clean install -f xwiki-platform-core/xwiki-platform-notifications/xwiki-platform-notifications-ui; mvn clean install -amd -f xwiki-platform-core/xwiki-platform-notifications/xwiki-platform-notifications-test -pl :xwiki-platform-notifications-test-docker -Pquality,integration-tests,docker; spd-say "DONE" and this time around it just failed on a timeout like the master branch...
I probably forgot to update my local branch.

[ERROR] Errors: 
[ERROR]   AllIT$NestedNotificationsIT>NotificationsIT.ownEventNotifications:408 » Timeout Timeout while waiting [20] sec on notification count. Expected: [1] - Latest value received: [0].
[INFO] 
[ERROR] Tests run: 12, Failures: 0, Errors: 1, Skipped: 0