ISTWCMS-5878 Remove form.inc file which is related to gesso only

includes/form.inc

-<?php
-
-/**
- * @file
- * Form template functions.
- */
-
-/**
- * Implements template_preprocess_input().
- */
-function gesso_preprocess_input(&$vars) {
-  $vars['required'] = isset($vars['element']['#required']) ? $vars['element']['#required'] : NULL;
-  $vars['type'] = isset($vars['element']['#attributes']['type']) ? $vars['element']['#attributes']['type'] : NULL;
-  $vars['dropbutton'] = isset($vars['element']['#dropbutton']) ? $vars['element']['#dropbutton'] : NULL;
-}
-
-/**
- * Implements template_preprocess_fieldset().
- */
-function gesso_preprocess_fieldset(&$vars) {
-  $vars['type'] = isset($vars['element']['#type']) ? $vars['element']['#type'] : NULL;
-}
-
-/**
- * Implements hook_theme_suggestions_HOOK_alter().
- */
-function gesso_theme_suggestions_form_alter(array &$suggestions, array $variables) {
-  $form_id = $variables['element']['#form_id'];
-  $suggestions[] = 'form__' . $form_id;
-}