Formats the content of the modal popup window.
format_content(verbatim_content, style = FALSE)reactive with the formatted content
(character, expression, condition or reactive(1)
holding any of the above) the content to show in the popup modal window
(logical(1)) whether to style the verbatim_content using styler::style_text.
If verbatim_content is a condition or reactive holding condition then this argument is ignored
Formats the content:
concatenates if needed
styles if style is TRUE