Provide time.toInstant method

[jlaur]

This provides a convenience method for constructing a time.toInstant from various input types, similar to time.toZDT.

The main purpose and motivation is to simplify this:

var startTime = time.toZDT(lastUpdateItem).toInstant();
var endTime = time.Instant.now();

to the more straight-forward (and faster):

var startTime = time.toInstant(lastUpdateItem);
var endTime = time.toInstant();

Please note I have deliberately left out a few conversions provided by time.toZDT which I consider slightly misleading and/or bloated, for example considering a number to be a number of milliseconds to be added to now. This can be achieved by directly using the js-joda classes, e.g. time.Instant.now().plusMillis(500) which to me seems more readable than time.toInstant(500).

I was in doubt whether to even add time.toInstant() (without parameter) in favor of using time.Instant.now(), but it seems so commonly used for time.toZDT that I decided to leave it in for first review iteration to be discussed. I also provided those operations working directly on items, although I also have doubts about DecimalType and QuantityType.

Testing

var zoned = time.toZDT(items.TestDateTime);
var instant = time.toInstant(items.TestDateTime);
console.log("item: " + instant.toString());
console.log("instant: " + time.toInstant(instant).toString());
console.log("now: " + time.toInstant().toString());
console.log("zoned: " + time.toInstant(zoned).toString());
console.log("string: " + time.toInstant('2024-10-31T20:00:02Z').toString());
console.log("item quantity: " + time.toInstant(items.TestTime));
console.log("item decimal: " + time.toInstant(items.TestNumber));
console.log("item string: " + time.toInstant(items.TestInstantString));

console.log("zoned item quantity: " + time.toZDT(items.TestTime));
console.log("zoned item decimal: " + time.toZDT(items.TestNumber));

Output:

2025-01-05 23:12:23.749 [INFO ] [enhab.automation.script.file.test.js] - item: 2024-10-31T20:00:01Z
2025-01-05 23:12:23.752 [INFO ] [enhab.automation.script.file.test.js] - instant: 2024-10-31T20:00:01Z
2025-01-05 23:12:23.755 [INFO ] [enhab.automation.script.file.test.js] - now: 2025-01-05T22:12:23.754Z
2025-01-05 23:12:23.757 [INFO ] [enhab.automation.script.file.test.js] - zoned: 2024-10-31T20:00:01Z
2025-01-05 23:12:23.764 [INFO ] [enhab.automation.script.file.test.js] - string: 2024-10-31T20:00:02Z
2025-01-05 23:12:23.769 [INFO ] [enhab.automation.script.file.test.js] - item quantity: 2025-01-06T00:13:23.765Z
2025-01-05 23:12:23.771 [INFO ] [enhab.automation.script.file.test.js] - item decimal: 2025-01-05T22:12:33.770Z
2025-01-05 23:12:23.775 [INFO ] [enhab.automation.script.file.test.js] - item string: 2024-10-31T12:00:01Z
2025-01-05 23:12:23.778 [INFO ] [enhab.automation.script.file.test.js] - zoned item quantity: 2025-01-06T01:13:23.776+01:00[Europe/Copenhagen]
2025-01-05 23:12:23.781 [INFO ] [enhab.automation.script.file.test.js] - zoned item decimal: 2025-01-05T23:12:33.779+01:00[Europe/Copenhagen]

Resolves #412