Migrate Guidance engine to use AlkemioVirtualContributorEngine + back guidance chat with room

[valeksiev]

Description

Make the communication between the AI server and the guidance engine asynchronous

Acceptance criteria

• [ ] use the AlkemioVIrtualContributorEngine package for the guidance engine
• [ ] store guidance chats in Matrix in a special room of type guidance
• we can't wait for the response from sending a message to the guidance engine and keep the chat only in memory fin the frontend
• when a user sends a message to the guidance engine a particular room of type guidance with name ${user.communicationID-guidance is created, and the whole conversation is kept there
• the user can recreate the room, i.e. reset the chat, but by default, the conversation will persist between page refreshes
• this will make the guidance engine work in the standard flow we use for the rest of the chat-style interactions with engines we have
• we still need to keep sending the message through a special mutation resolver as it needs to handle guidance room creation/reset - the rest is standard communication flow. (subscribe to roomEvents, read the messages from the lookup room...)
• The room will be retrieved from the user entity, a field called guidanceRoom that can be null if the room has never been used or has been resetted, or can have a normal Room entity if it has messages.
• The first message Hi, this is Alkemio’s automated guidance chat. It can provide you with answers based on Alkemio’s documentation. What are you looking for? will never be in the matrix room, it is added artificially by the client in the user's language at the beginning of the conversation.
• The reset chat command in the widget window will delete the room
• [ ] a VC of type guidance should be created and a setting to the Platform entity for it should be added

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