Vue3 upgrade: vue2-filters

Investigate/identify:
- whether we can use this library in Vue3
- what is missing to be able to use it (or when it will be available)
- alternate packages (or whether we can change our code as needed)
- what if we stop using this package altogether?

Refs:
- https://www.google.com/search?q=Vue2Filters+vue3
- https://v3-migration.vuejs.org/breaking-changes/filters.html

Start with the Vue 3 migration guide linked in the issue and investigate the vue2-filters package for Vue 3 compatibility. Compare available alternatives and the option of removing the package, then document a clear recommendation and the work needed to proceed.

Vom Indexierungsmodell aus dem Issue-Text verfasst.