feat: xcodebuildlog2sil

[nekrich]

Hey.
Sorry for the large amount of changes 😅.

1. Use one folder and Package.swift for all targets.

If you want to build just one target it's still easy, because swift CLI have the --target parameter.

```sh
swift build --target swan-swiftc
```

swan-xcodebuildlog2sil

I can't use swan-xcodebuild because it overrides code signing in my project and brakes build.

On my side when xcodebuild command executed it executed with a pipe | tee xcodebuld.log | xcbeautify, so I have logs.

What I needed is to convert logs to sil, so I created a new target swan-xcodebuildlog2sil which does the conversion.

Since there was a clear code duplication between swan-xcodebuild and swan-xcodebuildlog2sil I put log parsing and SIL sections saving logic in a shared lib SwanSwiftBuildLogParser.

If it's too much, I'm open to suggestion on how to split it.