Vue filters

What does this MR do?

Replace Vue filters with prototypes

How confident are you it won't break things if deployed?

Very

Links to related issues

Filters are removed from Vue 3.0 and no longer supported.

• https://v3.vuejs.org/guide/migration/filters.html

How to test

Reviewing each commit's changeset should be enough.

Checklist

• no unrelated changes
• added an entry to CHANGELOG.md