Move definitions and writing into separate library

[dsherret]

It would be useful to move the definitions and writing into a different library. The manipulation and writing could be useful for people who don't need the AST aspect of this.

• Add back typeChecker property on GlobalDefinition
• Add back tsNode properties.
• Need a way to inject runNodedDefinitionTests. Maybe a redesign.

[dsherret]

After a lot of thought: I'm not going to do this :(

Although I view doing this as more of a separation of concerns and an improvement, it creates a nightmare of code to maintain.

1. It's harder to maintain two projects.
2. I have to code generate definition classes for ts-type-info from ts-code-generator and add the properties I need.
3. I have to inject these new code generated classes into ts-code-generator.
4. I have to figure out a way to make it work with the binders and tests.

I'm going to open up a new change to merge a lot of the code I did in ts-code-generator back into this project. It will be nice to have everything under one roof again. I was not enjoying it.