Blacklist modules when stepping through source code

Hi! (Love pudb, been using it for a long time now).

This is a feature request that just came up for a way to blacklist modules when `next`ing. The reason being that `t` is great when you're not switching stack frames, or switching but then switching back immediately, but for other times, say, when debugging an application running in an event loop or using big chunks of a large library where you want to skip the module running the event loop or the third-party code, it'd be nice to have a way to blacklist.

If you don't have time for this, consider it a reminder for myself, I'll try to get to it at some point if I beat you to it.

Thanks.

Start by tracing how the debugger handles the `next` and `t` stepping commands. Determine where module names can be configured or checked during stepping, then define and test behavior that skips blacklisted event-loop or third-party modules while preserving normal frame navigation.

Written by the indexing model from the issue text.