"Copy only when installing" for "Embed App Extensions"

[RomanPodymov]

Hello.
Thank you for XcodeGen.
In this pull request I fixed #947. Added onlyCopyExtensionsOnInstall and using it the same way as onlyCopyFilesOnInstall from #912 but for app extensions.
Also, I think onlyCopyFilesOnInstall should be renamed to onlyCopyFrameworksOnInstall.

[yonaskolb]

Thanks for this @RomanPodymov. Would there be cases where onlyCopyExtensionsOnInstall would be a different value to onlyCopyFilesOnInstall? Otherwise we could just use the same property

[RomanPodymov]

Hello @yonaskolb
Well, I have a project where I should have selected Embed App Extensions / Copy only when installing and unselected Embed Frameworks / Copy only when installing.
That's why I think that onlyCopyFilesOnInstall is not a good name for this property, it should be something like onlyCopyFrameworksOnInstall.
@zjkuang What do you think?

[RomanPodymov]

Hello @yonaskolb
It works for me if I select both Embed App Extensions / Copy only when installing and Embed Frameworks / Copy only when installing. If you want I can use onlyCopyFilesOnInstall for all Copy only when installing checkboxes.

[yonaskolb]

@RomanPodymov I think sticking with onlyCopyFilesOnInstall that controls all the copying is good for now. If down the line people need more discrete options we can look at adding onlyCopyFrameworksOnInstall and onlyCopyExtensionsOnInstall, but I don't think they should be necessary

[RomanPodymov]

Hello @yonaskolb
Now onlyCopyFilesOnInstall is using for all phases where possible.

[tkachenkovv]

@yonaskolb
Hello.
Thank you for XcodeGen.
We REALLY need separate checkboxes for "Embed App Extensions" and "Embed Frameworks"