Model Templates for Seq2Seq (#9251)

* adapt cookie cutter

* fix copy past statement

* delete copy statements for now

* remove unused import from template

* make doc rst

* correct config docstring

* correct training

* correct inputs processing tf enc dec

* make style

* adapt templates

* clean tabs

* correct tensor -> Tensor naming

* correct indent

* correct templates

* fix the test

* break lines to avoid > 119

* Apply suggestions from code review

tests/test_modeling_tf_bart.py

@@ -94,7 +94,7 @@ class TFBartModelTester:
         self.batch_size = 1
 
         # first forward pass
-        outputs = model(input_ids, use_cache=True)
+        outputs = model(input_ids, attention_mask=attention_mask, use_cache=True)
 
         output, past_key_values = outputs.to_tuple()
         past_key_values = past_key_values[1]