refactor: Remove ixml refs in ProgramCall

[abmusse]

Part of #96

[abmusse]

ProgramCall Class Unit Tests
constructor
✓ creates and returns an instance of ProgramCall with lib and function set
toXML
✓ returns pgm XML
addParam
✓ appends param to pgm xml
✓ regular contains by='val'
✓ data structure contains by='val'
✓ regular contains by='val', with io='both'
✓ data structure contains by='val', with io='both'
addReturn
✓ appends return to pgm xml

8 passing (11ms)

[abmusse]

Looks like ProgramCall.addParam Could be simplified by creating another function that handles adding data structure parameters.

That way we could avoid the recursive calls to addParam.

This is out the scope of this PR therefore I will open a separate issue to track this.

[kadler]

This looks good to me, other than addParam, which needs to be overhauled, but we'll do that in a separate PR. @markdirish can you double check I didn't miss anything?

[markirish]

It looks good to me.

I understand why we want to remove iXml, its a behemoth of a class and has a bunch of constants that can be extracted much more gracefully. I do think there is some value in having the XML templates in some sort of single location (even if thats a "single location" for each class, so a ProgramCall only needs and knows about the the templates that is uses) ... I guess you could argue that the functions ARE themselves ARE that single location. This definitely looks like a step in the right direction