feat: add default modules and configurations for sequencer presets

[stanlou]

Summary

This PR introduces new classes in the stack package that provide ready-to-use defaults for modules and configuration.

What’s Included

Default Modules & Configs

• DefaultModules and DefaultConfigs
  • Centralized helpers that return the default module set and configuration for each supported option.
  • Designed to be composable and easy to override.

Sequencer Defaults

• DefaultSequencer and DefaultSequencerConfig
  • Provide fully configured, ready-to-use sequencer setups for:
    • inmemory
    • development
    • sovereign

AppChain Defaults

• DefaultAppChain and DefaultAppChainConfig
  • Provide fully configured, ready-to-use AppChain setups for:
    • inmemory
    • development
    • sovereign

Goal

The goal of this change is to:

• Reduce boilerplate for common setups
• Provide clear defaults
• Make it easy to bootstrap a Sequencer or AppChain while still allowing customization and overrides