[OH3] HowTo perform sendHttpGetRequest and sendHttpPutRequest in order to read/write through REST API

[Bruce_Osborne]

@opus

t is the device which runs openHAB which tries to get something from itself.

It is a service on the device ( & executed by a user) trying to get information from the openHAB service, outside of openHAB. The fact it is running on the same device does not matter to OH.