Provide Available Function Names in clasp run

[grant]

Expected Behavior

• clasp run by itself should give a list of possible function names.
  • This would be possible by the newish functionSet property. (8/2/2018)

Actual Behavior

We don't use functionSet.

[takanakahiko]

How do we display function names?

example :

1. switch arg functionName to optional. ( clasp run [functionName] [--nondev] )
2. If we don't provide a functionName , use Inquirer to list function names.

[grant]

Use inquirer to prompt the user for function names, like we do for create, clone, etc.

1. clasp run [functionName]
2. If we don't have the functionName, use inquirer#prompt to get the name. Provide a list of possible names from here: script.projects.getContent#files[N]#functionSet[O]#name (map over all files)
3. script.run with the name.

Eventually add autocompletion like this: https://www.npmjs.com/package/inquirer-autocomplete-prompt#example

[grant]

I added fuzzy filtering to the autocompletion. For some reason, the inquirer prompt wasn't quite working when I tried it.