[Commands] Return the same workspace object in getActiveWorkspace()
[Commands] Return the same workspace object in getActiveWorkspace()

getActiveWorkspace() shouldn't recreate workspace objects and should
return the same object on consecutive calls.

JGiola/swift-package-manager,JGiola/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,abertelrud/swift-package-manager,sschiau/swift-package-manager,apple/swift-package-manager,haskellswift/swift-package-manager,apple/swift-package-manager,sschiau/swift-package-manager,sschiau/swift-package-manager,abertelrud/swift-package-manager,vmanot/swift-package-manager,JGiola/swift-package-manager,vmanot/swift-package-manager,apple/swift-package-manager,haskellswift/swift-package-manager,sschiau/swift-package-manager,apple/swift-package-manager,vmanot/swift-package-manager,haskellswift/swift-package-manager,JGiola/swift-package-manager,abertelrud/swift-package-manager,vmanot/swift-package-manager,vmanot/swift-package-manager,abertelrud/swift-package-manager,haskellswift/swift-package-manager,apple/swift-package-manager,JGiola/swift-package-manager