[things] Add Thing class & Get Thing(s)

[florian-h05]

Closes #89.

Improvements

• a Thing class which represents an openHAB Thing, that e.g. holds the label, but also allows to set the enabled state
• getThings to get an Array of all openHAB Things
• getThing to get a single Thing

Testing

DO NOT USE ON PRODUCTION AS THIS MODIFIES A THING!!

const { things } = require('openhab');

const allThings = things.getThings();
console.info(allThings);
const astroThing = things.getThing('astro:moon:e66c230447', true);
console.info(astroThing);

const thing = allThings[0];

function analyzeThing (thing) {
  console.info('Bridge UID: ' + thing.bridgeUID);
  console.info('Thing label: ' + thing.label);
  console.info('Thing location: ' + thing.location);
  console.info('Thing sttaus: ' + thing.status);
  console.info('Thing detailed status: ' + thing.statusInfo);
  console.info('ThingTypeUID: ' + thing.thingTypeUID);
  console.info('Thing UID: ' + thing.uid);
  console.info('Thing is enabled: ' + thing.isEnabled);
}

analyzeThing(thing);

thing.setLabel('new label');
thing.setLocation('living room');
thing.setEnabled(false);

analyzeThing(thing);