Improve uni v3 auto router implementation

[LukSteib]

Goal

Fix the known auto router related problems

Context

During the implementation of the auto router (see #531) we faced the following problems that have been ignored for now:

• We're regenerating pools in a different moment than when we fetch price (see here)
• We cannot assume that tokens used for the route are always available via the maker chainlog (see here)

This issue is meant to fix these two problems and improve the current implementation

Tasks

• Fix pool regeneration problem
• Fix unknown token problem