`seedWords` used to be stored on the metamask state temporarily at
certain points. This hasn't been the case since #5994, but references
to this state remained. All of the logic remained for correctly updating
these `seedWords`, handling them during navigation, and scrubbing them
from the state.
However the state was never updated in practice. The `seedWords` are
still returned by `verifySeedPhrase`, and they're still stored in
component state in a few places. But they aren't ever set in the Redux
metadata state or the Preferences controller.
All references to this state have been removed, along with any logic
for interacting with this state. A few unused actions were removed as
well.
* eslint: Check for unused function arguments
* eslint: Ignore unused '_' in argument list
Also allow any number of '_' e.g., '__' or '___' which is to be used sparingly
* Remove and rename unused arguments
* Refactor and fix styling for first time flow. Remove seed phrase from persisted metamask state
* Fix linting and tests
* Fix translations, initialization notice routing
* Fix drizzle tests
* Fix e2e tests
* Fix integration tests
* Fix styling
* Fix migration naming from 030 to 031
* Open extension in browser when user has not completed onboarding