[jsscripting] Extend mapping of openhab-js classes to native openHAB counterparts

[florian-h05]

Addon part of openhab/openhab-js#98.

Description

This PR extends the target type mapping inside the JS Scripting addon to also translate the following openhab-js classes to their native openHAB Java counterparts when passing to Java methods:

• openhab-js Item -> org.openhab.core.items.Item
• openhab-js Quantity -> org.openhab.core.library.types.QuantityType

Regarding the updated bnd file: I hope I did the right (if I understood the docs correctly I did), but would be nice if one could have a look and verify that it is correct what I did.

Testing

Use the following script to test:

// Check JS-Item -> openHAB Item translation
actions.BusEvent.sendCommand(items.Temperature, "0 °C")

// Check JS-Quantity -> openHAB QuantityType translation
var QuantityType = Java.type('org.openhab.core.library.types.QuantityType')
QuantityType.valueOf('50 cm').add(Quantity('5 m'))

... or trust me given the simplicity of the code when comparing to the existing and well-working code.

[florian-h05]

@jlaur Can you please review this?

[jlaur]

@florian-h05 - I'm also not confident with bnd files, perhaps another @openhab/add-ons-maintainers could have a look?

[florian-h05]

@digitaldan Are you confident with bnd files?

[digitaldan]

Are you confident with bnd files?

No, although the changes look pretty straight forward to me

[wborn]

LGTM!