API: include user activation and sign-in status

[yoyoyonas]

• Gitea version (or commit ref): 1.14.1
• Git version: 2.17.1
• Operating system: Ubuntu 18.04, Gitea Binary Download
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No
• Log gist:

Description

active and prohibit_login can both be set via PATCH /admin/users/{username}, but are not included in the output of GET /admin/users or GET /users/{username}. Imho those are important information when working with the user list and should be added.