feat(order_execution): adds OrderManager

[shawnkchan]

Summary

Raising this PR to get feedback on my implementation for the order execution logic. This PR covers Order execution - Order Parsing and Order execution - Node Sequencing.

This PR contains the following features:

1. OrderManager class
   • Receives an Order message from the Order topic
   • Validates the order
   • Exposes API for OrderExecutor to sequence through the nodes and edges of the Order
2. GraphValidator class
   • Checks that the graph in an Order is valid
3. OrderGraphElement class
   • Parent class to Node and Edge class
4. Node class
5. Edge class
6. Order Class
7. Unit tests for OrderManager and GraphValidator

NOTE: IStateManager.hpp is a temporary class for mocking the StateManger in the unit tests.

[sauk2]

Thanks for all the great work on this!
This is a solid iteration and the direction looks good. To make it easier to review, test and merge this safely, I would like to suggest breaking the work into smaller pieces. This will make it easier to validate each part and keep the main stable.

Some high-level feedback:

• Retarget this PR to develop instead as we are holding off on pushing larger changes directly to main.

• Let’s merge PR feat(types): create C++ structs for VDA5050 2.0.0 spec #6 first as it introduces hard types that both the OrderManager and StateManager can use. Getting those in first will reduce a lot of duplication.

• Split the order and state logic into separate branches. Right now, this PR mixes order-related code with state-related code. To keep responsibilities clear,

  • OrderManager should focus strictly on order handling.
  • StateManager should focus strictly on state tracking.
  • The execution layer should serve as the bridge between the two.

  This separation would help us avoid having order-related classes directly mutate state and it keeps the architecture more testable.