Align integration tests with mainnet behavior

[Neotamandua]

Summary

The current integration tests execute calls directly against the EMT contract, which does not accurately replicate mainnet behavior. On mainnet, such calls (by sending a transaction) would be routed through the transfer contract, triggering an inter-contract call (ICC) to the EMT contract.

To align the tests with mainnet behavior, we should modify the test setup so that:

• The created VM session includes the transfer contract.
• Each test against the EMT contract is executed as a call to the transfer contract, containing call_data for an ICC to the EMT contract.

Additionally, we should investigate whether further adjustments to the VM (e.g., Config) are necessary. We may also need to mock transitory logic.