[interop] Add Support for Namespaces

[nikeokoronkwo]

Fixes #399
Fixes #416
Fixes #437
Fixes #420

This issue adds support for namespaces, including generating code for namespaces, and performing lookup on namespaces/modules using qualified names, to map such names to actual TS declarations. Only exported declarations from the namespace are generated for, reducing the number of unnecessary declarations generated for.

The TS compiler recognizes it as a named module, allowing for an easy transition to module-based code generation (see #424).

The generated code is an extension type with static members to represent the namespace items.

• Variables and Functions are mapped to static properties and methods, respectively.
• Classes and Interfaces are generated prefixed by the namespace name (i.e Foo.Bar becomes FooBar), and for classes, a static method is provided to redirect to the constructor of the class, matching the same structure as the constructor function.
• Namespaces are also generated prefixed by the namespace name, and a static getter is provided to access the namespace code as so.

Also:

• This also supports nested namespaces, as seen in the example code.
• This also supports cross-referencing by preloading the declarations into the nodemap, and updating them once a member has been implemented.
• Import typealiases import Name = Namespace.Interface are resolved inline when inside of a namespace. External import typealiases, or exported ones are converted to type aliases. This does not work for import = require yet.
• Namespace Imports are supported, although as of now, the types are deducted and referenced rather than handling the namespace import.

Tasks

• Support Namespaces
• Support Qualified Names
• Support Namespace vs Global Type Resolution
• Support Import Typealias
• Support Namespaced Imports

[nikeokoronkwo]

@srujzs Just a final check: good to go?

[srujzs]

Yes, LGTM! Thanks for the changes!