Race condition not showing all events from the websocket

[jorgeepc]

Describe the bug
We have a race condition where the web app could not receive some event logs from the web socket. It could happen because after we run a test, we need to subscribe to the /event resource using the web socket, therefore there is a time between sending the web socket subscription and the server registering it where some event logs could have already happened.

To Reproduce (not easy to reproduce)
Steps to reproduce the behavior:

1. Create a test with a failed trace
2. You should see the test run page
3. Go to the trace tab
4. Sometimes some events from trace stage are missing

Expected behavior
We should receive all the event logs from the server. There was already a PR to introduce a temporary buffer in the subscription manager (it was causing some issues around tests/transactions so probably it needs to be revisited).

Screenshots
Our current approach is to get the initial logs from the rest /events endpoint, you can see in the screenshot that it returns the events that are already in the DB:

At the same time we subscribe to the web socket updates, however we start getting the events after the subscription is registered by the server:

[xoscar]

We'll keep an eye on this and if it becomes too big we can decide how to solve it