fix(migration): route CSV migrator to dedicated page

The migration list linked all migrators to the 'migrate.service' route
by name, which loads MigrationHandler.vue. For the CSV migrator this
would result in a 400 error since it requires the multi-step
MigrationCSV.vue flow with config. Now CSV migrators link to
'migrate.csv' instead.

frontend/src/views/migrate/Migration.vue

@@ -4,10 +4,10 @@
 		<p>{{ $t('migrate.description') }}</p>
 		<div class="migration-services">
 			<RouterLink
-				v-for="{name, id, icon} in availableMigrators"
+				v-for="{name, id, icon, isCSVMigrator} in availableMigrators"
 				:key="id"
 				class="migration-service-link"
-				:to="{name: 'migrate.service', params: {service: id}}"
+				:to="isCSVMigrator ? {name: 'migrate.csv'} : {name: 'migrate.service', params: {service: id}}"
 			>
 				<img
 					class="migration-service-image"