feat: Conversation update API for sla_policy_id (#8973)

- Add an endpoint for updating conversation attributes (priority / sla_policy_id )
- Swagger spec
- minor chores around the conversation API/spec

Fixes: https://linear.app/chatwoot/issue/CW-2100/feat-backend-api-to-update-the-sla-of-a-conversation

app/controllers/api/v1/accounts/conversations_controller.rb

@@ -36,6 +36,10 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
     end
   end
 
+  def update
+    @conversation.update!(permitted_update_params)
+  end
+
   def filter
     result = ::Conversations::FilterService.new(params.permit!, current_user).perform
     @conversations = result[:conversations]
@@ -110,6 +114,11 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
 
   private
 
+  def permitted_update_params
+    # TODO: Move the other conversation attributes to this method and remove specific endpoints for each attribute
+    params.permit(:priority)
+  end
+
   def update_last_seen_on_conversation(last_seen_at, update_assignee)
     # rubocop:disable Rails/SkipsModelValidations
     @conversation.update_column(:agent_last_seen_at, last_seen_at)
@@ -176,3 +185,5 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
     @conversation.assignee_id? && Current.user == @conversation.assignee
   end
 end
+
+Api::V1::Accounts::ConversationsController.prepend_mod_with('Api::V1::Accounts::ConversationsController')