Handle cases where site creation fails in New-PnPSite

[jackpoz]

Type

• [x] Bug Fix
• [ ] New Feature
• [ ] Sample

Related Issues?

Improves #4082

What is in this Pull Request ?

Handle cases where site creation fails in New-PnPSite by throwing a clearer exception. The previous code would try to dereference returnedContext even when null, throwing a Object reference not set to an instance of an object. exception. This happens because Framework.Sites.SiteCollection.Create() returns null in some cases, like if the site url was not retrieved after enough tries.

I'm not sure if the message should be changed. At this point of the callstack we have no idea what went wrong during the creation and if the site was fully created and configured or not. It might be that there was an issue only when retrieving the SPO ClientContext but everything else worked fine. In any case, anything should be better than an unhandled null exception 😃