[EPIC] Steering API integration test suite (medium/low prio endpoints)

Follow up from: [EPIC] Steering API integration test suite (hig... (#204 - closed)

Medium and low priority

• /api/v1/categories/**
• /api/v1/funding-categories/**
• /api/v1/languages/**
• /api/v1/licenses/**
• /api/v1/music-focus/**
• /api/v1/link-types/**
• /api/v1/types/**
• /api/v1/topics/**