YAML-to-Python code generator improvements

[elliotgunton]

The "v1" of the YAML-to-Python generator is due to be released. It is a bit rough around the edges in terms of generating Pythonic code, so this is a list of potential issues described in #1444, roughly listed in low-to-high effort order:

• Skip api_version and kind in the Workflow params
• Split long parameter value strings
• Generate arguments in dict format
• Sort Python arguments using the same algorithm as YAML keys (name first, then basic types, then lists/dicts)
• Generate script-decorated functions for script templates using a Python image/command

Completed:

• Update invocator context name to use steps/dag/container_set Completed in Format Python code output from Hera CLI using black #1465
• Skip trailing comma to allow formatter to decide whether to collapse list of args into one line Completed in Format Python code output from Hera CLI using black #1465