Rename a project

[marksherman]

Process to rename is currently to Save As, then delete the original. This is more complicated than necessary, and is especially problematic when template files and starter code projects are being used.

Request a native "rename" option in the project menu that executes that works as one user operation.

(friction observed by @jsheldonmit in addition to myself and others)

[ewpatton]

Assigning this to @ColinTree due to PR #1011

[wxbit]

I think renaming a project by copy and delete is a bad idea. But we have to do that, because the project name is a part of filename in ProjectFileData,and used as objectid in GCS. So, we should use appname as project name show in the list, and use projectId in filenames. When user create a new project,we create a project without any file first.and then use the projectid to naming the default files.