Improve logic for launch configuration executable path

[bkhouri]

Looking at the code base, the extension is making an assumption as to the location of the executables targets location.

See

vscode-swift/src/debugger/launch.ts

Lines 133 to 137 in 96192cb

	const targetPath = path.join(
	BuildFlags.buildDirectoryFromWorkspacePath(folder, true),
	"debug",
	target
	);

This will fail when the default build system for swift build changes. It would be better to use the --show-bin-path command line option passed to swift build to determine the build output location.

❯ swift build --show-bin-path
/Users/bkhouri/Documents/git/public/swiftlang/swift-package-manager-2/.build/arm64-apple-macosx/debug

❯ swift build --show-bin-path --configuration release
/Users/bkhouri/Documents/git/public/swiftlang/swift-package-manager-2/.build/arm64-apple-macosx/release

❯ swift build --show-bin-path --build-system swiftbuild
/Users/bkhouri/Documents/git/public/swiftlang/swift-package-manager-2/.build/arm64-apple-macosx/Products/Debug

❯ swift build --show-bin-path --build-system swiftbuild  --configuration release
/Users/bkhouri/Documents/git/public/swiftlang/swift-package-manager-2/.build/arm64-apple-macosx/Products/Release


❯ swift build --show-bin-path --configuration release --scratch-path /my-temp
/my-temp/arm64-apple-macosx/release

❯ swift build --show-bin-path --configuration release --scratch-path /my-temp --triple my-triple --build-system swiftbuild
/my-temp/my-triple/Products/Release