Please describe feature/problem details and the solution you'd like.

Hello. I recently used the websocket request feature and there is an area that could be improved, so I am creating this issue.
I use Elixir Phoenix to develop and test websocket APIs. Phoenix makes it easy to create websocket APIs through an abstracted module called Channel, and Channel allows clients to send various types of messages (after connecting). However, Thunder Client currently only allows one message per websocket request.
Currently, I'm developing by saving the messages I send somewhere and copying and pasting them, but I thought it would be nice to be able to pre-write multiple messages on the websocket request screen and select and send them whenever needed. I think the workflow for developing and testing websocket APIs could be vastly improved with this feature.

Describe alternatives you've considered
Often, I create messages that I need to send in the Docs tab, and it would be nice to have a copy button or a button to send the message in each code block.

Are you using the free version/paid version/trial:
I'm using starter plan.