Report generic project load or reload progress

Today, there is no real indication of how much progress the server is making when loading projects. The most information is in the C# logs where we indicate when we've loaded a project.

 
We should add a mechanism on the server side that sends progress reports to the client on project loading.
The client can then use these reports to display a progress bar indicating what is happening and how far along we are in project load.

We can use this to also move automatic restore entirely server side (and report using the same progress mechanism).