SwaggerEditor@next(standalone): navigation sidebar

[tim-lai]

Problem: It can be difficult to find and scroll through a large definition.

Proposed solution: a component in EditorPaneBarLeft that:

• filter by operation/schema/tag/etc
• organize by sections
• support OpenAPI 2.x definitions
• support OpenAPI 3.0 definitions
• support OpenAPI 3.1 definitions
• support AsyncAPI 2.x definitions