Create alias for "WebJobs" app settings to "Functions"

We create a few default app settings in functions projects (locally and in cloud) to things like `AzureWebJobsStorage` which I think would be more clear if named `AzureFunctionsStorage`. Many of our users have never used or are even very aware of WebJobs and this may help clarify the purpose of some of these settings and config.

No files, tests, or entry points are named. Start by locating where default app settings such as AzureWebJobsStorage are created for local and cloud Functions projects, then trace how existing names are consumed; done should include a compatible AzureFunctionsStorage alias without breaking the existing setting.

Written by the indexing model from the issue text.