To simplify the migration of individual curation toolbar modules, we should separate the rendering of said modules.

Currently, they are added to the vue App in one line of code: https://github.com/wikimedia/mediawiki-extensions-PageTriage/blob/master/modules/ext.pageTriage.views.toolbar/vue/App.vue#L22. We should separate them into individual items so we can add vue components in between the un-migrated backbone ones.