[json] support references in schema associations

Issue Type: <b>Bug</b> ## Steps to repro in `settings.json...` ```json "json.schemas": [ { "url": "http://localhost:8080/my.schema.json#/$defs/inner_schema", "fileMatch": [ "/**/tests/testfile.json" ] } ] ``` in `./tests/testfile.json` ```json { "name": "example" } ``` in `./schemata/my.schema.json` ```json { "$schema": "https://json-schema.org/draft-07/schema#", "$id": "https://example.com/schemata/my.schema.json#", "type": "boolean", "default": true, "$defs": { "inner_schema": { "type": "object", "properties": { "name": { "type": "string" } }, "additionalProperties": false } } } ``` in root folder `package.json` I'm using a simple web server to serve the local schemas. ```json { "dependencies": { "http-server": "^13.0.1" }, "scripts": { "dev": "http-server ./schemata -p 8080", "start": "npm run dev&" } } ``` To serve the files in ./schemata locally... `$ npm start` Disable/Enable the JSON>Format setting to force the schema to be pulled. ## Incorrect Behaviour in Latest Version Version: 1.63.2 Commit: 899d46d82c4c95423fb7e10e68eba52050e30ba3 Date: 2021-12-15T09:37:28.172Z (5 days ago) Electron: 13.5.2 Chromium: 91.0.4472.164 Node.js: 14.16.0 V8: 9.1.269.39-electron.0 OS: Darwin x64 20.6.0 1. change the "name" property to something else. Observe that intellisense DOES NOT flag an error. ###Logging from http-server [2021-12-20T21:14:41.762Z] "GET /my.schema.json" "undefined" (node:16871) [DEP0066] DeprecationWarning: OutgoingMessage.prototype._headers is deprecated (Use `node --trace-deprecation ...` to show where the warning was created) [2021-12-20T21:14:42.083Z] "GET /my.schema.json" "undefined" ## Correct Behaviour in October Version Version: 1.62.3 Commit: ccbaa2d27e38e5afa3e5c21c1c7bef4657064247 Date: 2021-11-17T07:59:13.865Z (1 mo ago) Electron: 13.5.2 Chrome: 91.0.4472.164 Node.js: 14.…