fix: emit the schemas with an nested in the route schemas

[Tony133]

Proposal:

The ref resolver collects every subschema having an $id it meets while resolving the route schemas (that is what TypeBox Type.Recursive(..., { $id: 'Node' }) produces: an inline schema referencing itself with $ref: 'Node'), and rewrites the references to it as #/definitions/def-N. However components.schemas / definitions were built from ref.definitions() before the routes were processed, so:

• the reference was left dangling (Missing $ref pointer "#/components/schemas/def-0")
• the schema was left inline, $id included, which Swagger 2.0 rejects as well

Changes:

• referenceInlineDefinitions() (lib/util/definitions.js): after each ref.resolve(), the subschemas matching a collected definition are replaced by { $ref: '#/definitions/def-N' } and returned. They are matched by $id, not by identity, because the resolver ignores the duplicates of an $id (the same schema used by two routes). Shared schemas, anchors ($id: '#...') and the root definitions added by the resolver (already handled by hoistDefinitions) are left alone.
• The resolve returned by Ref() (lib/util/add-hook.js) applies it and accumulates the definitions in ref.inlineDefinitions, including the ones nested in a collected definition.
• Both generators add ref.inlineDefinitions to the top-level definitions after the routes loop, through the usual prepareOpenapiSchemas / prepareSwaggerDefinitions.
• hoistDefinitions now treats the definitions known to the resolver as top-level ones: otherwise a shared schema consumed by def-1 was hoisted again as def-1-def-0.

For the schema of the issue, def-0 is now emitted with its recursive $ref, and treeNodes.items becomes { $ref: '#/components/schemas/def-0' }. The document validates with swagger-parser in both OpenAPI and Swagger 2.0.

An inline $id schema is now handled exactly like a shared schema referenced with $ref: for instance a querystring property with an $id becomes a $ref parameter, as a $ref to a shared schema already does.

Note:

• In Swagger 2.0 a schema with an $id used as the root of a response still keeps $id: 'todo.com' inline (pre-existing, unrelated to the resolver collection).
• A shared schema object copied inline in a route (same $id as an addSchema() one) is left inline, as before.

Fixes #865