Port backtest engine and kernel to Rust

[filipmacek]

Pull Request

• moved TimeEventAccumulator to separate accumulator.rs file from engine.rs
• created new system crate which contains NautilusKernel and its config scaffold methods with todos
• created various backtesting config like BacktestEngineConfig, BacktestVenueConfig, BacktestDataConfig, and BacktestRunConfig with docs
• created struct BacktestEngine and scaffold methods with todos
• created Environment enum in common crate
• finished and added docs to DataEngineConfig
• added StreamingConfig and DataCatalogConfig in persistence crate