Feature request: show filtered line but dim it

Filtering is very useful to cleanup the stacktrace.
However often the stacktrace could be strange to read especially when there are anonymous entries. It would be nice if there were an option to mark filtered entries so the filtered line could be outputed also but style with render kid as less important entry. Of course this makes only sense in color output mode.

Start by locating the stacktrace filtering and color-output rendering paths. Confirm how filtered entries are currently omitted, then define the option's behavior so filtered lines remain visible but are styled as less important only in color output; done means the option works without changing default filtering.

Written by the indexing model from the issue text.