Create custom emoji on instance-level

Problem

This issue makes it so custom Emoji are possible to be made/removed on GitLab instance level.

Scope

  • Upload custom Emoji from instance-level
    • GitLab administrators can add custom Emoji (meaning that this option should be made accessible to any group member)
      • Name and avatars of people who added custom Emoji are shown with the custom Emoji
    • Validations to make sure that the Emoji labels to not collide with existing ones
    • Validations for reasonable-sized images
  • The custom Emoji will be available to all places in the instance where Emojis are entered
    • Emoji auto completer
    • Emoji menu
    • Emoji reaction search
  • Geo / object storage support
  • Performant Emoji picker

Design

  • to do