Release 1.21.0

🚀 Enhancement

• #548 Avoid scrolling in multiple select on classifcation (@lagartoverde)
• #540 Feat/phonenumber convention sync (@Dachamelemon)
• #541 Refactor: Introduce generic Agent resource (@mirdono)
• #542 Fix: make names of AGB, APB, and IGS clickable on positions page (@mirdono)
• #539 Hide purpose and planned end date when not filled in (@claire-lovisa)
• #537 post processing to open editor links in a new tab (@lagartoverde)
• #536 Make all organizations clickable in persons module (@claire-lovisa)

🐛 Bug Fix

• #547 Fixed secondary number validation (@Dachamelemon)

🏠 Internal

• #544 Use woodpecker ci instead of drone - follow up (@claire-lovisa)
• #543 Tests fix and cleaning (@aliokan)

Committers: 5

• Alexander van den Berghe (@mirdono)
• Claire Lovisa (@claire-lovisa)
• Laurent Deketelaere (@aliokan)
• Oscar Rodriguez Villalobos (@lagartoverde)
• @Dachamelemon