Extended test cases to test io-package.json against the schema

[oweitman]

Extended test cases to test io-package.json against the schema https://github.com/ioBroker/ioBroker.js-controller/blob/master/schemas/io-package.json

This ensures that an error not addressed or detected in VSCode or a similar environment does not result in a release on GitHub and NPM.
It also prevents additional implementation effort for checks in the repochecker.

To implement this, we can use this package https://www.npmjs.com/package/jsonschema

testing/src/tests/packageFiles/index.ts

Line 135 in 764da3d

describe(`Check contents of io-package.json`, () => {