Add Xcode template

[AnasAlhasani]

Describe your changes

Added Xcode template to automatically generate Lasso components including Flow and Screen for more details please check lasso-template

Notes:

• Flow template:

  • I have added support to specify the concrete type of the FlowModule, available types:
    • FlowModule and NavigationFlowModule. the generated enums i.e MyFlowModule: FlowModule {} are left empty and deferred specifying the type of the Output and RequiredContext for the implementer best judgment (because there are multiple different cases).
    • NoOutputFlow and NoOutputNavigationFlow.

• Screen template:

  • I made generating a view controller optional (Enabled by default) because there would be a case where you have a previously implemented viewController with a specific logic and you only want to just add a Screen and Store.

  • I couldn't find a simple way to configure generating a Screen when there is NoOutput, NoAction, or EmptyState (8 possible cases, not sure if they are valid in a production code). I just decided to keep it simple.

Thanks!

[AnasAlhasani]

Thank you for reviewing my work, @g-mark! I have updated the PR, please have a look.