Add support to create things from automation script

[ThaDaVos]

Just like one can do with items already, would love to be able to create things from JavaScript/Typescript too - this way I could use the automation addon to fully define my system - better said, use script to automate the definition - for example use arrays and logic to create stuff instead of repetitive defining them in files.

Your Environment

• openHAB version used (check Main UI -> About):
• openhab-js version used (run console.log('openhab-js ' + utils.OPENHAB_JS_VERSION) from a JS script): N/A
• Operating System and version (e.g. desktop or mobile, Windows 10, Raspbian Buster, ...): N/A