Third party settings support

Context module doesn't work with Third Party Settings when you add a block via context it doesn't create associated block config entity.

Because of this, we can't integrate context module with Menu Multilingual and at the same time use third party settings. See related issue #2956990: Settings no longer stored as third party settings.

I can add them directly to this config, but then it's not possible to delete these custom settings during my module uninstall process:

      'blocks' =>
      array (
        'f1e391e6-942d-4d38-ae87-570103a4e8f8' =>
        array (
          'id' => 'system_menu_block:account',
          'label' => 'User account menu contexttt',
          'provider' => 'system',
          'label_display' => 'visible',
          'level' => '1',
          'depth' => '0',
          'region' => 'header',
          'weight' => '0',
          'custom_setting' => 'value',
          'context_mapping' =>
          array (
          ),
          'theme' => 'bartik',
          'css_class' => '',
          'unique' => 0,
          'context_id' => 'test',
          'uuid' => 'f1e391e6-942d-4d38-ae87-570103a4e8f8',
        ),
      ),

The question is, what's the best way to add my settings to context's blocks config?