Add TFBartForSequenceClassification (#20570)

* read to load

* base functionality

* revert init

* fix dummy data

* moving right along

* moving right along

* finally

* cleanup

* pull out comment

* add test

* update docstring for main class

* flake comments and rewriting copies from make repo-consistency`

* remove irrelevant differences/accidental spaces

* put copies back after space removals

* mid

* final test pass

* stray comment

* update test file

* update test file

* fixup

* black

* missed

* black missed one more

* sytle

* add doc update

* fix order of output class

* comment

* Revert "comment"

This reverts commit 03f86b6948808461939cc8ad4ad74305dfb67700.

* remove redundant function, and redundant reshape

* move change out of common

* style

* put common spaces back

* reorder kwargs in output

* doc style

docs/source/en/model_doc/bart.mdx

@@ -157,6 +157,11 @@ A list of official Hugging Face and community (indicated by 🌎) resources to h
 [[autodoc]] TFBartForConditionalGeneration
     - call
 
+## TFBartForSequenceClassification
+
+[[autodoc]] TFBartForSequenceClassification
+    - call
+
 ## FlaxBartModel
 
 [[autodoc]] FlaxBartModel