Remove separate altitude parameter from Astro binding

[kaikreuzer]

When approving my auto-discovered Sun thing, I got this in my log:

15:52:30.491 [INFO ] [smarthome.event.ThingAddedEvent     ] - Thing 'astro:sun:local' has been added.
15:52:30.493 [INFO ] [me.event.ThingStatusInfoChangedEvent] - 'astro:sun:local' changed from UNINITIALIZED to INITIALIZING
15:52:30.500 [ERROR] [ding.astro.handler.AstroThingHandler] - Astro parameters geolocation could not be split into latitude and longitude, disabling thing 'astro:sun:local'
15:52:30.501 [INFO ] [me.event.ThingStatusInfoChangedEvent] - 'astro:sun:local' changed from INITIALIZING to OFFLINE

The issue is that the discovery now adds ",," in the geoLocation config parameter of the Thing, while it expects the altitude to be filled into the dedicated "altitude" parameter instead.

As we will soon have a location context, which also includes altitude information, I think it would make most sense to remove the "altitude" parameter of Astro things and rather mark the geoLocation parameter to be of context "location", which implicitly can hold an optional altitude value.