Address arch board feedback

[maririos]

All languages:

• Before next arch board in Jan 2021, put aside an hour with the service team to discuss how to return strongly typed models from prebuilt methods (we can start with .NET and Python, all invited though) Design a way to strongly type prebuilt models #16330
  • Consider wrappers for custom form models in the discussion as well
• Consider parsing FormType Consider parsing FormType #16384
• Expose locale parameter in method as an extensible enum instead of string Expose locale parameter in method as an extensible enum instead of string #16660

.NET ITEMS

• Move ModelName out of options bag for training and composedModel endpoints [FR] Make modelname as a default parameter #16381
• Code sample lines are too long, find a way to split code so users don't have to scroll horizontally. Consider also making variable names in code sample shorter Improve samples #16661
• In SelectionMarkState, flip Unselected and Selected so they corresponding to 0 and 1 In SelectionMarkState, flip Unselected and Selected so they corresponding to 0 and 1 #16662

[maririos]

Issues created for every feedback point. Will follow up on the individual issues