[jcbrand]

The headless capabilities that @converse/daemon and @converse/cli (#4200) need, split out so they can land on their own. None of them are daemon-specific, so the web UI can use them too.

New in headless

• api.contacts.resolve: resolve a name to roster contacts
• api.rooms.discover: list the rooms a MUC service hosts, following XEP-0059 paging
• sendMessage options to reply to, or correct, a given message
• api.reactions.send: send XEP-0444 reactions, encrypted when the chat uses OMEMO
• api.archive.search: XEP-0431 full-text search of the server archive. Matches are held in their conversations, with placeholders for the history around them that isn't fetched yet.
• fetchArchivedMessages returns the archive query's answer
• Message.getArchiveID and Message.getReferenceID

Fixes

• Chats no longer hang on servers without XEP-0191
• afterMessageCreated listeners after the reactions plugin get the message
• A resent message that fails again keeps its new failure
• Disco entity and resource session stores are keyed by account
• A contact goes offline when an unknown resource goes unavailable
• api.rooms.open with a list of JIDs no longer throws a ReferenceError
• A moderated message is found when the room's history has a gap
• Name resolution doesn't match or name a contact by its JID
• sendMessage refuses to correct a message that isn't an editable one of ours

Known gap

An archive search leaves a room's private messages out, because there's no correct place to hold them yet. They used to land in a 1:1 chat with the room's JID. Holding them in the occupant's chat is follow-up work.