Genesis Files Default to Nothing in Emulator Initialization

**Description:** I've been reviewing how the emulator loads Genesis files upon start and found that it defaults to Nothing. I want to clarify if this is intentional or if there's an option to provide Genesis files explicitly. If not, is there a plan to support this functionality, especially with the upcoming Conway upgrade?

**Steps to Reproduce:**

- Check the code responsible for loading the genesis files (_cardano-node-socket-emulator_).
- Notice that the `main` uses the default implementation (`defaultNodeServerConfig` which is set to Nothing).

**Expected Behavior:** An explicit genesis file should be required or loaded if available.

**Actual Behavior:** Defaults to Nothing without indicating the need for a genesis file.

**Questions:**

Would you happen to know if this is the intended behavior?
How does the emulator load Genesis files upon the start?

**Additional Information:** This could affect configurations when simulating different blockchain states during testing or development.