Add additional options for setting the current environment colors

Problem/Motivation

Currently, the module requires the user to set the title, bg colors and fg colors through configuration in settings.local.php. This works, however, I always find myself having to duplicate these values in the switcher.

It would be preferable to be able to set the local environment colors through two other methods:

1. A machine name of one of the environments defined on the environment switchers page could be used instead, with the values for the environment title, background color, and foreground color pulled from the switcher values defined in config.

2. One of the environments defined on the switchers page should be selectable on the module settings page, and stored in the Drupal state (so the value is does not become part of configuration).