[Flow Control] Integrate Policy Configuration into EPP Plugin Model #1794
Description
What would you like to be added: The core Flow Control policy configuration should be integrated into the standard EPP YAML-based plugin system. This would allow users to define priority bands and select and configure different Inter-Flow (Fairness) and Intra-Flow (Ordering) policies directly in their configuration.
Why is this needed: Currently, key policies like the available priority bands, Inter-Flow Fairness (BestHead), and Intra-Flow Ordering (FCFS) are hardcoded within the EPP. Making these components pluggable is essential for user extensibility and aligns the Flow Control layer with the consistent plugin model used by other layers in the project.