Change the way the allow and deny list is handled.

[JanFellner]

I really like your extension but the idea how allowed and denied list is handled (interpreted) is kind of wieeerd :) to me.
I don´t know any system that does it the way the extension does it.

In general speaking i would assume something needs to be in the allowed list to get formatted at all and there may be exclusion from that allowed list. Furthermore i also allow filenames to be part in that list instead of just extensions.

Thus the concept of this PR ist.

• An extension and or filename needs to be in the allowed List but not in the denied list to get formatted

Especially if i would generally like to get .h files formatted but e.g. not resource.h files which are written by the ide.
This PR solves that issue (or missing functionality)

[mynkow]

10x for this PR. Any idea how to handle existing user settings? Users may have configured settings in .config file or in the VS settings. If we do apply this PR directly, would it break their setup? I think so.

May be we can add a boolean flag which states Use legacy filters and if users have custom setup that flag will be ON running the old code. Otherwise use the new way.

Just thinking out loud...