INN-171 Simulate abbreviated Leios pipelines

[bwbush]

The goal is to develop a rudimentary, protocol-level simulation of Leios for a single node and for a simplified (short) Leios pipeline. This differs from full-fledged multi-node simulation (with faithful network diffusion) of the full protocol. The simulation will be exercised for an uncongested and for a congested scenario.

Acceptance criteria

• Simulated simplified (short) Leios pipelines for a single node, only partially faithful
• Execute simplified simulation for example uncongested scenarios
• Execute simplified simulation for example congested scenarios