Add basic GitHub CI workflow

[Matejkob]

I have noticed that the is not CI on this repository; so I'm creating this this pull request that introduces a basic Continuous Integration setup for the repository and incorporates a Swift Macro Compatibility Check to ensure the library's compatibility across multiple swift-syntax versions.

1. CI Setup:

   • macOS:

     • Runs the workflow on macOS 14 with Xcode versions 15.0, 15.4, and 16.0.
     • Steps include checking out the repository, selecting the correct Xcode version, printing the Swift version, building the package, and running the tests.

   • Linux:

     • Runs on the latest Ubuntu with Swift versions 5.9, 5.10, and 6.0.
     • Includes checking out the repository, building the package, and running tests.
     • Uses a Swift container for each version.

   • Windows:

     • Runs on the latest Windows image with Swift versions 5.9.1 (macros support added in 5.9.1), 5.10, and 6.0.
     • The Swift toolchain is installed using compnerd/gha-setup-swift.
     • Steps include checking out the repository, installing Swift, building the package, and running tests.

2. Swift Macro Compatibility Check:

   • Motivation: The action ensures the library remains compatible with multiple swift-syntax versions, which is critical for libraries utilizing Swift macros introduced in Swift 5.9.
   • Problem Addressed: Different libraries might depend on different versions of swift-syntax, causing dependency conflicts. The compatibility check ensures that our library can work across a range of swift-syntax versions, making it a good citizen in the Swift ecosystem and preventing conflicts when users combine multiple libraries that depend on swift-syntax.
   • Features:
     • Tests against all minor versions and major versions of swift-syntax (e.g., 509.x, 510.x, 600.x).
     • Includes the option to run tests and verbose output.
     • Helps catch potential compatibility issues early, ensuring smooth integration with other libraries.