Debugger: Consistenly use 'state' instead of 'status'

Fix inconsistent naming e.g. in QtDeclarativeEngineDebug by always
using 'state' instead of 'status'. This is in line with the other
source code, which also seems to favor 'state'.

Change-Id: I65a7a3bd0eb7dfffeb37b5f8dad15b0a4a78de70
Reviewed-by: Aurindam Jana <aurindam.jana@nokia.com>