kuttl should warn/abort on duplicate resources

[porridge]

This a "wishlist" type issue, not a real bug, but too small to be KEP-worthy.

What happened:

My test should have been asserting the existence of two similarly-named objects.
However due to a copy-paste mistake it was actually asserting the existence of one object twice (I forgot to change the name when copy-pasting the object definition).

What you expected to happen:

kuttl should abort, or at least warn about such case.

How to reproduce it (as minimally and precisely as possible):

Include the same object twice in an assert file.

Environment:

• KUTTL version (use kubectl kuttl version): v0.15.0