Improved support for OpenAPI sources

[edgarrmondragon]

Feature scope

Taps (catalog, state, stream maps, tests, etc.)

Description

Tasks

Beta Give feedback

1. Leverage schema and other API details from OpenAPI spec file #308
   Accepting Pull Requests evergreen extract kind/Feature migrated from gitlab valuestream/SDK +6
2. Swagger Codegen for Singer taps based on OpenAPI spec: RFC #1701
   Accepting Pull Requests extract migrated from gitlab stale +4