New functions architecture - re-introduce the previous chat-related functionality

[tubamos]

Description

Re-introduce two previous functionalities that were removen when we transitioned to the firebase functions:

• Voice
• Change dropdown UI component so that it sends multiple LLMs requests in the firebase functions

User story

• As an end user
• I want a way to send queries to multiple LLMs, receive the responses and let them nattared back to me via a voice interface
• so that I can compare the results faster.

Acceptance Criteria

• Voice functinoality has been re-introduced
• The user can select multiple LLMs via the dropdown and send requests to multiple LLMs

Definition of Done

• The feature has been fully implemented.
• The feature has been manually tested and works as expected without critical bugs.
• The feature code is documented with clear explanations of its functionality and usage.
• The feature code has been reviewed and approved by at least one team member.
• The feature branches have been merged into the main branch and closed.
• The feature utility, function and usage have been documented in the respective project wiki on github.