feat: OpenAPI 3.1 support (#8367)

- New top-level field - `webhooks`. This allows describing out-of-band webhooks that are available as part of the API.

- New top-level field - `jsonSchemaDialect`. This allows defining of a default `$schema` value for Schema Objects

- The Info Object has a new `summary` field.

- The License Object now has a new `identifier` field for SPDX licenses. This `identifier` field is mutually exclusive with the `url` field. Either can be used in OpenAPI 3.1 definitions.

- Components Object now has a new entry `pathItems`, to allow for reusable Path Item Objects to be defined within a valid OpenAPI document.

- `License` and `Contact` components are now exported and available via `getComponent`

- New version predicates and selectors for `isOpenAPI30` and `isOpenAPI31`. This avoids needing to change the usage of `isOAS3` selector.

- New OAS3 components: `Webhooks`

- New OAS3 wrapped components: `Info`, `License`

test/unit/xss/anchor-target-rel/info.jsx

@@ -1,7 +1,7 @@
 import React from "react"
 import { render } from "enzyme"
 import { fromJS } from "immutable"
-import Info, { InfoUrl } from "components/info"
+import Info, { InfoUrl, License } from "components/info"
 import { Link } from "components/layout-utils"
 import Markdown from "components/providers/markdown"
 
@@ -10,6 +10,7 @@ describe("<Info/> Anchor Target Safety", function(){
 	const components = {
 		Markdown,
 		InfoUrl,
+		License,
 		Link
 	}
 	const baseProps = {