Bot avatar:

* For now, only one avatar possible,
* uses mod_random_vcard_peertubelivechat,
* mod_random_vcard_peertubelivechat has a new option with the avatar
  list (instead of a hardcoded avatar number)
* Peertube lists available avatars files, and pass it to mod_random_vcard_peertubelivechat

server/lib/prosody/config/paths.ts

@@ -9,6 +9,9 @@ interface ProsodyFilePaths {
   certsDirIsCustom: boolean
   modules: string
   avatars: string
+  avatarsFiles: string[]
+  botAvatars: string
+  botAvatarsFiles: string[]
   exec?: string
   execArgs: string[]
   execCtl?: string