Homestyx hydra

R1:edaf17f3fe51

Make chart function argument parsing modular/flexible with 900 pages of error messages

Summary:
Depends on D20444. Ref T13279. Instead of ad-hoc parsing and messages, formalize chart function arguments.

Also, add a whole lot of extra type checking.

Test Plan: Built and charted various functions with various valid and invalid argument lists, got sensible-seeming errors and results.

Reviewers: amckinley

Reviewed By: amckinley

Subscribers: yelirekim

Maniphest Tasks: T13279

Differential Revision: https…
Repository: R1 hydra
Commit Date: Apr 23 2019