Improve if directive formatting

[belav]

Some things that don't work yet.

1. nested directives
2. if the final else needs a specific combination, that won't be in the set
3. we don't actually look at not's correctly. Meaning #IF !ONE && TWO is parsed as ONE TWO, instead of just TWO
4. related, for something like #IF ONE || TWO we only need one of the two symbols
5. we may want to allow specifying symbolSets by file
6. #121

[belav]

https://github.com/belav/aspnetcore/blob/main/src/ProjectTemplates/Web.ProjectTemplates/content/BlazorServerWeb-CSharp/Startup.cs has some good examples

[belav]

https://stackoverflow.com/questions/25789994/microsoft-solver-foundation-sat-cnf