[Users] Implement "remember me" functionality

[netsensei]

Symfony Security also features a "remember me" component. This is currently not yet implemented in the Datahub.

Detailed description

From the documentation:

Once a user is authenticated, their credentials are typically stored in the session. This means that when the session ends they will be logged out and have to provide their login details again next time they wish to access the application. You can allow users to choose to stay logged in for longer than the session lasts using a cookie with the remember_me firewall option:

This is a new feature. This would allow users to stay logged in for longer periods of time, which could be useful if a user performs intensive labour in the interface.

Context

This would benefit administrators and managers

[netsensei]

See also #66

[netsensei]

Deferring this as an enhancement for a next version.