User customizable ambiguous characters for Unicode Highlight

<!-- ⚠️⚠️ Do Not Delete This! feature_request_template ⚠️⚠️ --> <!-- Please read our Rules of Conduct: https://opensource.microsoft.com/codeofconduct/ --> <!-- Please search existing issues to avoid creating duplicates. --> <!-- Describe the feature you'd like. --> I would like to set my own customized list of additional abmiguous unicode characters to be highlighted. As a person writing CJK characters daily, I have been using Highlight Bad Chars extension to avoid the annoyance that arises from the ambiguity of unicode glyphs. I'm very happy to see the latest vscode comes with a similar feature integrated, but I feel sorry to find that the list of ambiguous characters are not customizable. There are lots of candidates of possibly confusing sets of characters, so it would be better to ask the users to define the list of characters at their disposal.