Power Fx Versions Save

GA build on Nuget.org: https://www.nuget.org/packages/Microsoft.PowerFx.Core/1.2.0

GA build on Nuget.org: https://www.nuget.org/packages/Microsoft.PowerFx.Core/1.1.0

Release notes; https://github.com/microsoft/Power-Fx/blob/main/releasenotes/releasenotes-1.1.0.md

Many improvements, including:

1. Updates namespaces (see #361) - this is a breaking change from 0.2.1-preview.
2. More control over configuration and adding custom functions and optionsets.
3. publicly expose the syntax tree from the parser.
4. More functions implemented in interpreter.
5. Better config story for adding custom functions
6. Better host marshalling, including add virtual RecordValues and ITypeMarshallers for marshalling .net objects.
7. OptionSet support
8. Improved error handling.
9. DisplayName support
10. ParseJson support.