Add automated test for "Add inclusive filters"

The manual test is here: Add inclusive filters

Existing automated coverage

• NotificationsSettingsIT#customFiltersAndLiveData: Creates an inclusive (Notify) custom filter with a location, "A page is modified" and the Email format through the "Add filter" modal and checks it in the Live Data. Its effect is not checked.
• NotificationsSettingsIT#filterAndWatchedPage: Watching or unwatching a page or space creates the matching inclusive or exclusive filters.
• NotificationsEmailsIT#notificationsEmails: Triggers the daily email job and checks the email, with no custom filter.
• ScopeNotificationFilterTest#withTopLevelInclusiveFilters: Unit-level query generation for top-level inclusive scope filters.

Missing automated coverage

• Create pages a/b/c/d/e; user U1 has an email address, does not follow the wiki, picks the Daily email frequency and turns on the Pages alert and email toggles.
• As U1, add a Notify filter on page b (page and children), event type "A page is modified", channel Alert.
• As U1, add a Notify filter on page c (page and children), event type "A page is modified", channel Email.
• As another user, update pages a, b, c, d and e.
• Trigger the "Notifications daily email" scheduler job.
• Assert that U1's notification tray shows update events only for b, c, d and e.
• Assert that the email received by GreenMail lists update events only for c, d and e.

Suggested location: xwiki-platform-core/xwiki-platform-notifications/xwiki-platform-notifications-test/xwiki-platform-notifications-test-docker/src/test/it/org/xwiki/platform/notifications/test/ui/NotificationsEmailsIT.java

Found by comparing the XWiki 18.4.4 manual test runs against the automated tests on master (a0055f10a1a).