chore: FillAdjustor and clean up JS router and unused functions [TKR-403]

[dekz]

Description

• Removed the concept of Fill parents or having an array of fills for the path. The Rust router just returns the amount to fill against that path and we find the nearest FillData to that amount.
  • This means we no longer need to "collapse" or join those individual fills into a single one.
• Removed the concept of CollapsedPath
• In the Rust router flow we'd always create a single Fill. Removed the support for arrays of fills
• Splits the FeeSchedule and GasSchedule it was confusing to have one transformed into the other.
• Added gas to the Fill

Samples: Info returned from the Sampling process, mostly input output and FillData
Fill: Total amount we wish to fill on each path, input and output may be modified. Includes adjustedOutput to account for costs.
Path: A collection of Fills. Includes adjustedRate to account for the output and costs

In c56b2b9 we are now adjusting our FEE SOURCES which use use to calculate costs (in maker/taker assets). During sampling we perform a lite check for ETH/makerToken and ETH/takerToken. Then we can go gas * gasPrice -> makerTokenAmount

Previously we took the median, which was ok when liquidity was fairly spread out. But as liquidity for certain pairs begins to centralize, it is likely better to find the best price, adjusted for cost. Adjusting for cost will help us remove super expensive pools, like some of the big curves, which aren't worth arbing.

Testing instructions

Types of changes

Simbot as at a42ae30

Checklist:

• Prefix PR title with [WIP] if necessary.
• Add tests to cover changes as needed.
• Update documentation as needed.
• Add new entries to the relevant CHANGELOG.jsons.