feat: fundamental codebase refactor

[b4rtaz]

This PR introduces fundamental changes in Distributed Llama. Work in progress.

List of changes:

• ✅ Introduced an abstract neural network model with opcodes to describe neural network behavior
• ✅ Completely restructure the project
• ✅ Batch processing to support evaluation and prediction #138
• ✅ Speed up matmul operation for the evaluation

In progress:

• ⌛ ARM and AVX2 optimalisation for all op codes
• ⌛ Restore chat, api