Check for interpolation errors while accessing YAML objects

If a wrong key/index will be used to get a parameter
using 'get_variable_from_yaml', groovy may return a bunch of different
interpolation errors, or hide the actual error by returning 'null' object.

Try to catch such errors and show the actual info about it.

Task:       PRODX-19061
Related to: PRODX-16926

Change-Id: I4aed8f9988e854f7e0aec0cadeb065e8dae31603
1 file changed