[EVM Reader] Substitute the use of Websocket subscription by a Polling strategy

[fmoura]

📚 Context

The use of Websocket subscription shows lots of problems when used against APIs like Alchemy and Infura.

✔️ Solution

The safest approach is to use a polling strategy instead. So the loop to check for new inputs should ditch the "New head events" in favor of a time based one. The polling rate must be configurable

Subtasks

-[ ] Also improve "getLastBlock" call. Move it outside App Group loop