Module REFACTORING

Problem/Motivation:

1. A lot of deprecated code - (removed in patch)
2. Folder for the favicons. - Added folder for the favicons 'public://responsive_favicons/'. By default, BUT you can alter it with hook responsive_favicons_get_favicons_directory. Since added step with files deletion (folder cleanup) before updating icons set
3. Added validation - You cant create folder without name for now
4. Added browsers cache favicons independence - to implement a new set of favicons after refreshing you should run cache rebuild only (no need to flush browsers cache)
5. Added service to use form submit handler from other classes and a lot of hooks. So now you can use it like this (for subsites usage):
   $path_context = 'ss_' . $entity->id();
   \Drupal::service('responsive_favicons.form_submit_helper')
   ->formSubmitter($form_state, '', '', '', $path_context, 'responsive_favicons', 'just_files'); And then add three hooks:
   moduleName_responsive_favicons_get_public_uri_alter(&$path, $path_context){}
   moduleName_responsive_favicons_normalise_extra_path_alter(&$extra_path, $path){)
   moduleName_responsive_favicons_load_all_icons_with_cache_context_alter(&$cache_context){}

Fixed in patch

User interface changes. - No changes, just added validation

API changes - Added service and hooks to use it from subsites for example

Data model changes - No changes, its still files tree, but added folder 'responsive_favicons' by default to avoid data losing because of rewrite feature