feat: Line Channel (#2904)

- Ability to configure line bots as a channel in chatwoot
- Receive a message sent to the line bot in chatwoot
- Ability to reply to line users from chatwoot

fixes: #2738

app/controllers/webhooks/line_controller.rb

@@ -0,0 +1,6 @@
+class Webhooks::LineController < ActionController::API
+  def process_payload
+    Webhooks::LineEventsJob.perform_later(params: params.to_unsafe_hash, signature: request.headers['x-line-signature'], post_body: request.raw_post)
+    head :ok
+  end
+end