[KD] [KD64] Introduce KdpPrintBanner and use it in all places where we print the...

[KD] [KD64] Introduce KdpPrintBanner and use it in all places where we print the (now consistent) banner instead of copying the code over and over again.

I still don't like that we're copying code between KD and KD64 instead of sharing it.
But as both modules are totally distinct at the moment, I won't be the one introducing shared functions between them.

This is a follow up to 50ae5e7c5268222718174221366169e2b115b06a, which TortoiseGit accidentally turned into a "Message only" commit...
Never hit ALT+Y by mistake! ;)