Invalid Emoji ID

Environment

• Installation type: From Source
• Pleroma version: 2.6.0
• Elixir version: 1.14.0
• Operating system: Debian
• PostgreSQL version: 15.6

Bug description

The id property of Emoji objects (e.g. in EmojiReact activity) is not always a valid URI.

According to the ActivityPub spec, IDs are "Publicly dereferencable URIs". An URI may only contain a limited set of allowed characters in its path component. However, sometimes Pleroma uses an unescaped whitespace there, which is not allowed. For example:

https://pleroma.example/emoji/dino walking.gif

To comply with the URI standard, non-allowed characters should be percent-encoded:

https://pleroma.example/emoji/dino%20walking.gif