feat: add exportable internal functions

[willemneal]

fixes #491

Submodule functions decorated with @nearBindgen are wrapped in the same manner as those exported from the entry file. This also helps to signal that this function will be a module export to the reader.

For example,

index.ts

export { foo} from "./foo"

foo.ts

// @ts-ignore
@nearBindgen
export function foo(): string {
  return "hello";
}

Unfortunately Typescript doesn't allow decorators on

[mehtaphysical]

Looks good! Cool feature.

[mehtaphysical]

nice! just realizing now that:

export { myFunc } from './path.ts'

was always possible as long as myFunc had no inputs or outputs.

[willemneal]

Yep!