Add module TypeScript definitions and compatibilty

[phooning]

Overview

Projects using @elyra/canvas are not able to read and import modules if using TypeScript - at best, modules and functions will be unknown. I propose adding TypeScript definitions to modernize the canvas and make it friendlier for JSDoc support, future project adoption, and maintainability.

I've taken the liberty to create an definition implementation here: https://github.com/phooning/canvas-ts/blob/main/%40elyra/index.ts
Where we've attempted to define function output, arguments, interfaces, and types throughout the canvas as well as appending the appropriate documentation as a JS/TSDoc comment, markdown formatted, above the function for the user to see.

As an experimental end result by using vitejs and rebuilding the canvas, I was able to alias type definitions under another namespace to import and read into TypeScript React projects and frameworks.

Example JSDoc compatibility after building with TypeScript comments:

1. Elyra canvas should have TypeScript support either through an alternative build-phase addition (rollup TypeScript) or
2. External d.ts files such as above linked into rollup and/or
3. A submission with an external package with https://github.com/DefinitelyTyped/DefinitelyTyped

I would be happy to help work and PR this with whoever might be interested!

Todos:

• common-properties
• Removing and cleaning up unknown/unsupported types
• Fully defining an interface and extending user custom types (like a Node<T>)