refactor: update dependencies and fix resulting errors

Upgraded JSON Schema from version 6 to version 7
Upgraded TypeDoc version to latest
Replaced 'jsonschema' with 'json-schema' package to better comply with 'ts-json-schema-generator'
Replace JSON Schema validation with AJV in areas where it wasn't used previously
Removed commander help output as it causes strange issues

test/validate.spec.ts

@@ -15,7 +15,7 @@
 import {Logger} from '@openstapps/logger';
 import {expect} from 'chai';
 import {existsSync, mkdirSync, writeFileSync} from 'fs';
-import {Schema} from 'jsonschema';
+import {JSONSchema7 as Schema} from 'json-schema';
 import {slow, suite, test, timeout} from 'mocha-typescript';
 import {join} from 'path';
 import rimraf from 'rimraf';