Cache settings via admin section

It just popped into my mind.

Right here: https://api.backdropcms.org/api/backdrop/core%21includes%21cache.inc/fun...

 static $cache_objects;
  if (!isset($cache_objects[$bin])) {
    $class = settings_get('cache_class_' . $bin);
    if (!isset($class)) {
      $class = settings_get('cache_default_class', 'BackdropDatabaseCache');
    }

We are using settings_get function to properly direct cache features based on settings.php

But it is really old way and we have better solution - JSON settings!

So how about to keep this data in config('cache.settings') ?

This way cache settings could be easy transferred between different websites.

Also we can ADD admin/settings/cache page and not experienced users will be able to select different (available) methods for different bins.

Related: #716 #1413