Describe the enhancement requested

Instead of using internal sub-packages, the idea is to move all the targets into the main package, expose to external only “Arrow”, as now.

This improvements allow to Xcode developer to use the package opening just one package. Because in this moment working on Xcode you need to open three different windows. Embrace Swift simplicity

This improvements allow contributors to use the visibility key “package” to open some feature only into the package, thought the targets.

This improvements allow to build, test and run, using Swift command line without custom scripts.

Also, move “go-swift” in the same package, using “executableTarget” allow “swift run —product go-swift” to run the target without building.

Also, new structure is more efficient during CI/CD caching and building.

I can’t prove using documentation this is more “swifty” but using my experience on swift and check a lot of different package on “swift package index” https://swiftpackageindex.com/ I can assume this simplicity is the most used on the community.

Folder proposal:
|-arrow-swift
|—sources
|—-arrow
|—-flightArrow
|—-go-swift (rename in “data control” or something else more explicit to the functionality)
|—tests
|—-arrowtest
|—-flightarrowtest