Allow publish command to output to local .json file

[pietervp]

In some scenarios, people do not want to host their connector on our platform. Give them the option to output a valid json definition of the connector (including its js source) which can be loaded by SDK using this method:

https://github.com/chili-publish/studio-sdk/blob/f04fe9d44af65c9ea189b66243ce5a8c931ed8be/packages/sdk/src/controllers/ConnectorController.ts#L66

using the URL registration (they would need to host the json somewhere accessible)
https://github.com/chili-publish/studio-sdk/blob/f04fe9d44af65c9ea189b66243ce5a8c931ed8be/packages/sdk/src/types/ConnectorTypes.ts#L72

The expected JSON structure is the same as the POST endpoint consume