feat: Add macros from combine-interception-macros package

[maximkrouk]

Macros approach is aligned with https://github.com/pointfreeco/swift-dependencies
Now they are a part of this package, but have a separate target

Pros vs shared target:

• Optional use of macros, core features are available without use of macros (macros increase cold compilation time, so not everyone is down to depend on them)

Pros vs separate macros package:

• Much easier to maintain
• Easier to import

Cons vs separate macros package:

• swift-syntax has to be resolved even if client doesn't use macros (however compilation time is not affected if client opts-out macros)

Notes:

• This PR also sets up CI