Port functions file to lib

[brandenrodgers]

Description and Context

Porting the cli-lib functions logic into local dev lib. This is the logic responsible for handling the hs create function command to generate a CMS serverless function.

I made a few changes to the structure of this file:

• The main util functions in here now throw errors instead of returning anything or logging
• I added logging hooks into the main createFunction method
• I'm planning to move the code for the function into cms-sample-assets because that's a better place for it. It'll be easier to maintain the code when it's stored in a repo.

Screenshots

TODO

• I have not tested this out yet and I'm assuming there will be some bugs.
• Ask the CMS team if it's alright for me to move the function code into the sample assets repo

Who to Notify

[camden11]

One small comment, otherwise LGTM

[kemmerle]

I tested this out with the instructions you left on Slack, @brandenrodgers, and everything is working correctly for me 🚢