feat: restore the disturber content element, port the groups.swiss export

The 404 page (and other pages TYPO3 13 renders) contain disturber elements,
which logged 'no rendering definition' on every 404. The CType is back with
its TypoScript, templates and FlexForm; the TCA uses the TYPO3 13 API.

ep:groups-swiss replaces the TYPO3 10 scheduler tasks, which stopped with
PHP 7.4. It reads the calendar from MyE&P (contingents/calendar, synced from
bpn-connect) instead of bpn-connect directly, so it needs no new credentials,
and publishes all houses from groupsSwissHouses in secrets.php (or one house
given as arguments, as the scheduler tasks did). The ranges match the TYPO3 10
algorithm on 2000 random calendars; --dry-run shows them without sending.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

packages/ep_theme/Configuration/TypoScript/ContentElements/disturber.typoscript

@@ -0,0 +1,8 @@
+tt_content.disturber =< lib.contentElement
+tt_content.disturber {
+    templateName = Disturber
+    dataProcessing {
+        10 = EP\EpTheme\DataProcessing\TeaserImageProcessor
+        20 = EP\EpTheme\DataProcessing\FlexFormProcessor
+    }
+}