Transition to swift-macro-testing for Macro Testing (#16)

* use point frees macro testing library

* swift-format

* remove useless inline snapshots

Author: ajkolean

Package.resolved

@@ -19,6 +19,7 @@ let package = Package(
         ),
         .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.3.0"),
         .package(url: "https://github.com/SwiftPackageIndex/SPIManifest.git", from: "0.12.0"),
+        .package(url: "https://github.com/pointfreeco/swift-macro-testing", from: "0.4.0"),
     ],
     targets: [
         // Implementations of macros tested by tests
@@ -49,9 +50,9 @@ let package = Package(
             dependencies: [
                 "MacroToolkitExamplePlugin",
                 "MacroToolkit",
+                .product(name: "MacroTesting", package: "swift-macro-testing"),
                 .product(name: "SwiftSyntax", package: "swift-syntax"),
-                .product(name: "SwiftSyntaxMacros", package: "swift-syntax"),
-                .product(name: "SwiftSyntaxMacrosTestSupport", package: "swift-syntax"),
+                .product(name: "SwiftSyntaxMacros", package: "swift-syntax")
             ]
         ),
     ]