Add plugin apis to control spec design functionality

[nijikokun]

Is your feature request related to a problem? Please describe.

As a plugin author it would be nice to be able to have APIs for the design panes to hook into the design process.

Describe the solution you'd like

• Being able to control the language parser for the spec loaded
• Being able to hook into the spec loaded event
• Being able to hook into spec change event
• Being able to control the linter output
• Being able to control the validation errors
• Being able to control the sidebar output for a spec
• Being able to control the preview pane output for a spec
• Being able to hook into the tab change event (design -> debug) and override the request generation

Additional context

I may have missed some events here, but ideally, whatever would be required to move openapi support into a plugin would be evented and hooked 🙌

By providing above, we could move OpenAPI support to a plugin and allow plugin authors to write plugins to support other plugins, or plugins for OpenAPI features

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.