Support Jinja in non str Args

[gilesknap]

This PR updates the schema to make jinja rendering in arguments and values easier to use and cleans up some of the naming:

• all args now can be type OR a jinja string that should render to that type
• values and pre_values now can specify type and can be directly used as that type when referred to in Jinja.
• values and pre_values support the list type (Args do not)
• values and pre_values are renamed to post_defines and pre_defines respectively
• sample tests demonstrate these features
  • listarg: nonsense test to show use of jinja in args and defines, use of lists in defines
  • fastVacuum: a practical example of a complex interaction between fast vacuum master and fast vacuum channels - the example duplicates what is done in builder.py for dlsPLC support module.
• the global context object is renamed from utils to _global .