Add CLI interface for importing custom emoji (#8437)

bin/tootctl emoji import PATH_TO_TAR

Fix #8435

lib/cli.rb

@@ -2,10 +2,14 @@
 
 require 'thor'
 require_relative 'mastodon/media_cli'
+require_relative 'mastodon/emoji_cli'
 
 module Mastodon
   class CLI < Thor
     desc 'media SUBCOMMAND ...ARGS', 'manage media files'
     subcommand 'media', Mastodon::MediaCLI
+
+    desc 'emoji SUBCOMMAND ...ARGS', 'manage custom emoji'
+    subcommand 'emoji', Mastodon::EmojiCLI
   end
 end