EPIC: Replace all ethjs* packages with ethers package

This is a placeholder description. We should create subissues for all of the places where we need to replace. It is already in the dependency tree so bundle size is not the issue.

Start by inspecting the monorepo dependency tree to identify every place where an ethjs package is used. Create subissues for each replacement location, then verify that all ethjs packages have been replaced with ethers and that the dependency tree remains correct.

Written by the indexing model from the issue text.