Administrative User can end a conversation on their end

AS A Administrator I WANT to end an active chat session with a "terminate session" button in toolbox view. SO THAT i could resolve the conversation and assign the status to the chat.

Acceptance Criteria

[x] Upon clicking that button, I am prompted with options according to Figma: https://www.figma.com/file/JYnmhsKixyUSCSUXXfwTAA/B%C3%BCrokratt?type=design&node-id=247-5263&t=FK7U4DRyfM38Np9s-4. See also #33.
[x] After ending active chat, chat will be moved to chat history

buerokratt / Buerokratt-Chatbot

Administrative User can end a conversation on their end #83