Add Tilt integration test for Hello World

[a5-pickle]

Objective

Add an integration test that allows Hello World apps to speak to each other.

Definition of Done

In a new directory (probably called tilt in the root of the repository), build out how the tests should be organized and add a test that performs sendMessage and receiveMessage from each EVM and Solana contracts.

Please be mindful of other apps from new networks joining the test. For example, if a Hello World Aptos app is written, each app should interact with the other two apps (Aptos <> EVM and Solana, Solana <> Aptos and EVM, etc). We prefer the tests to be exhaustive, so each network's app interacting with all other networks' apps.