By Anu@Zyware: Alpha release of search404

saved the configuration form data correctly to config.search404.
install file changed to save the system configuration 404 page.
removed search_data() and corresponding functions(because in D8 there no such function),implemented using search404Controller.
get the default search form using \Drupal::service('search.search_page_repository').
changed goto using RedirectResponse.
removed apachesolr related search codes.
d7 corresponding varioubles changed to D8(from dev to alpha changes only).