* Splits `renderHtml` into three distict functions to prevent passing in mixed content types
* Moves the `inline` and `className` properties onto the `RenderOptions` structure

* Removes the `child` option for `IHTMLContentElement`. This is only used internally
* Delete some unused functions

* Remove Unused Html Content Renderer Extensibility

Removes a few options from the html content renderer that are currently not used

* Fix messageList

Fixes #14968

**Bug**
Due to https://github.com/chjj/marked/issues/829, markdown escapes inside of links are currently not rendered properly. This also can effect regular text that contains characters that are escaped when we convert them to markdown text.

**Fix**
For links, remove markdown escapes before rendering them.