BLIP: enable generation tests (#34174)

* blip2 tests

* instructblips

* copies

* fix slow tests

* fix

* uncomment this

* clean up after rebase

* should be model main input

* fix overwritten tests

* oops len should be multiple of frame number

* style

* fix some tests

tests/generation/test_utils.py

@@ -96,6 +96,7 @@ if is_torch_available():
 
 
 class GenerationTesterMixin:
+    input_name = "input_ids"
     model_tester = None
     all_generative_model_classes = ()
     max_new_tokens = 3