fix: removed unused util file

lib/src/utils/delta_x_utils.dart

@@ -1,80 +0,0 @@
-import 'package:html2md/html2md.dart' as hmd;
-import 'package:markdown/markdown.dart' as md;
-
-// [ character
-const int _$lbracket = 0x5B;
-final RegExp _youtubeVideoUrlValidator = RegExp(
-    r'^((?:https?:)?\/\/)?((?:www|m)\.)?((?:youtube\.com|youtu.be))(\/(?:[\w\-]+\?v=|embed\/|v\/)?)([\w\-]+)(\S+)?$');
-
-///Local syntax implementation for underline
-class UnderlineSyntax extends md.DelimiterSyntax {
-  UnderlineSyntax()
-      : super(
-          '<und>',
-          requiresDelimiterRun: true,
-          allowIntraWord: true,
-          tags: [md.DelimiterTag('u', 5)],
-        );
-}
-
-class VideoSyntax extends md.LinkSyntax {
-  VideoSyntax({super.linkResolver})
-      : super(
-          pattern: r'\[!\[',
-          startCharacter: _$lbracket,
-        );
-
-  @override
-  md.Element createNode(
-    String destination,
-    String? title, {
-    required List<md.Node> Function() getChildren,
-  }) {
-    final element = md.Element.empty('video');
-    element.attributes['src'] = destination;
-    if (title != null && title.isNotEmpty) {
-      element.attributes['title'] = title;
-    }
-    return element;
-  }
-}
-
-///This rule avoid the default converter from html2md ignore underline tag for <u> or <ins>
-final underlineRule =
-    hmd.Rule('underline', filters: ['u', 'ins'], replacement: (content, node) {
-  //Is used a local underline implemenation since markdown just use underline with html tags
-  return '<und>$content<und>';
-});
-final videoRule = hmd.Rule('video', filters: ['iframe', 'video'],
-    replacement: (content, node) {
-  //This need to be verified by a different way of iframes, since video tag can have <source> children
-  if (node.nodeName == 'video') {
-    //if has children then just will be taked as different part of code
-    if (node.childNum > 0) {
-      var child = node.firstChild!;
-      var src = child.getAttribute('src');
-      if (src == null) {
-        child = node.childNodes().last;
-        src = child.getAttribute('src');
-      }
-      if (!_youtubeVideoUrlValidator.hasMatch(src ?? '')) {
-        return '<video>${child.outerHTML}</video>';
-      }
-      return '[![$content]($src)';
-    }
-    final src = node.getAttribute('src');
-    if (src == null || !_youtubeVideoUrlValidator.hasMatch(src)) {
-      return node.outerHTML;
-    }
-    return '[![$content]($src)';
-  }
-  //by now, we can only access to src
-  final src = node.getAttribute('src');
-  //if the source is null or is not valid youtube url, then just return the html instead remove it
-  //by now is only available validation for youtube videos
-  if (src == null || !_youtubeVideoUrlValidator.hasMatch(src)) {
-    return node.outerHTML;
-  }
-  final title = node.getAttribute('title');
-  return '[![$title]($src)';
-});