Merge "list terms" page into "edit vocabulary" page

Problem/Motivation

A separate page for editing the fields of a vocabulary versus editing its structure is confusing and frustrating. Similar issue: #663946: Merge "List links" page into "Edit menu" page →

Proposed resolution

Combine vocabulary edit page and vocabulary term overview page

Remaining tasks

Postponed on 📌 [policy] Determine design for forms that have multiple actions Active
Fix the failing tests
Implement tweaks from [# 📌 Separate the menu settings from the 'add link' button Postponed

User interface changes

No more vocabulary term overview page. Terms will be shown on vocabulary edit page.

Before

Two separate forms:

After

API changes

None

Postponed until 📌 Separate the menu settings from the 'add link' button Postponed