XWIKI-22999: Activity stream should use list semantics

[Sereza7]

Jira URL

https://jira.xwiki.org/browse/XWIKI-22999

Changes

Description

• Added list semantics to the notification macro.

Clarifications

• The notification macro is used among other things in the activity stream. It's also used notably in the notification dropdown.
• In order to minimize the DOM changes (and also not have to change much the blocks in the HTMLRenderer), I used the aria role="listitem" instead of <li> in the notifier script service.

Screenshots & Video

Executed Tests

Successfully built wqith the changes:

• mvn clean install -f xwiki-platform-core/xwiki-platform-notifications/xwiki-platform-notifications-notifiers/xwiki-platform-notifications-notifiers-api -Pquality
• mvn clean install -f xwiki-platform-core/xwiki-platform-notifications/xwiki-platform-notifications-macro/xwiki-platform-notifications-macro-ui

Expected merging strategy

• Prefers squash: Yes
• Backport on branches:
  • None, this is a DOM change that could break extensions and customizations