Option to convert ANSI color sequences on message import.

It would be nice to have an option in SBBSEcho/QwkNet etc. So that on message ingress/import it converts simple ansi color sequences to corresponding CTRL-A codes.

This would allow for ANSI messages to be displayed while allowing line-count and full-screen readers to function more simply.

To consider, not sure how/where ansi display detection gets flagged or trigger, if it's a message attribute, this should run before any such check.