[bug] Ensure clients that always remember emails have an avenue to do so

[addisonbeck]

Type of change

• Bug fix
• New feature development
• Tech debt (refactoring, code cleanup, dependency upgrades, etc)
• Build/deploy pipeline (DevOps)
• Other

Objective

With Account Switching we tweaked the way logic determined if an email should be remembered or not. Instead of storing a specific boolean key to know whether or not we had a remembered email on init, we just check to see if a remembered email already exists. This works well for apps like web, where remember email is also controllable with an input, but not so much for apps that always remember email like browser and desktop.

Code changes

Instead of going back to the way things were and having client specific logic in the base login component, we should ensure that we always remember emails for clients that behave that way in the clients that need to special case.

This commit exposes a component variable that can be set by clients to determine if email should always be remembered.

Before you submit

• I have checked for linting errors (npm run lint) (required)
• I have added unit tests where it makes sense to do so (encouraged but not required)
• This change requires a documentation update (notify the documentation team)
• This change has particular deployment requirements (notify the DevOps team)