Move fee policy configuration from CLI args to config file

[jmg-duarte]

Description

Extract FeeFactor from shared::arguments into its own shared::fee_factor module, adding Serialize/Deserialize support

Requires https://github.com/cowprotocol/infrastructure/pull/4620 to be merged before

Changes

• Move FeePoliciesConfig, FeePolicy, FeePolicyKind, FeePolicyOrderClass, and UpcomingFeePolicies from autopilot CLI arguments to autopilot::config::fee_policy as serde-based config structs
• Read fee_policies_config from the TOML config file (flattened into Configuration) instead of CLI flags
• Update all e2e tests to construct fee policy config via Configuration structs and pass them through the config file

How to test

E2E + staging

[gemini-code-assist]

Code Review

This pull request refactors fee policy configuration from CLI arguments to a TOML configuration file. The changes are applied across the codebase, including updates to E2E tests. One review comment has been kept regarding a potential logic change in a test, as it does not contradict any established rules.

[fafk]

LGTM, left some nits.

[MartinquaXD]

Doesn't it make sense to not flatten the config here? Config files were related things get grouped together are easier to navigate, no?

In order to avoid weird naming originating from this one could consider naming this field fee_policies and the FeePoliciesConfig::fee_policies could be renamed to initial_policies (as opposed to upcoming_policies.

[jmg-duarte]

unflattened and variables renamed, let me know what you think