Create an Unresolved* typealias for all supported OpenAPI types

[andrewse02]

Motivation

Currently, when referencing OpenAPI types that may not be referenceable, it requires a very long and unintuitive type name (e.g., Either<JSONReference<OpenAPI.Request>, OpenAPI.Request>). We can clean this up, by exposing more usable, and practical typealiases to improve quality of life and speed while working on the generator.

Modifications

Added and used Unresolved* typaliases for:

• OpenAPI.Request
• OpenAPI.Response
• OpenAPI.Header
• JSONSchema

Result

New typealiases will be added, decreasing confusion, and increasing symmetry when using OpenAPI types.

Resolves

Resolves #12

Edits

1. Removed additions of Resolved* typealiases

[czechboy0]

Making all the Unresolved* aliases is great, but as you suggested, let's get rid of the Resolved* aliases, as they create an extra layer of indirection to clear types, like JSONSchema/OpenAPI.Parameter, and so on. Thanks 🙏

[czechboy0]

Looks great, thanks!

[simonjbeaumont]

@andrewse02 thanks for taking the time to clean this up. Just one minor nit from me—otherwise LGTM!