Add GLPN (#16199)

* First draft

* Fix logits calculation

* Improve tests

* Add copied from statements

* Fix base_model_prefix

* Improve implementation, upload new models

* Update design

* Fix integration test

* Add model to README and toctree

* Add document image

* Apply suggestions from code review

* Apply suggestions from code review

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* Add decoder_hidden_size attribute

* Update design of decoder

* Add DepthEstimatorOutput class

* Rename in_index to head_in_index and add feature extractor tests

* Apply suggestions from code review

* Apply suggestions from code review

* Update pretrained model name and add to doc tests

* Remove test.py script

* Update copied from statements and clean up

Co-authored-by: Niels Rogge <nielsrogge@Nielss-MacBook-Pro.local>
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

utils/check_repo.py

@@ -114,6 +114,7 @@ TEST_FILES_WITH_NO_COMMON_TESTS = [
 # should **not** be the rule.
 IGNORE_NON_AUTO_CONFIGURED = PRIVATE_MODELS.copy() + [
     # models to ignore for model xxx mapping
+    "GLPNForDepthEstimation",
     "ViltForQuestionAnswering",
     "ViltForImagesAndTextClassification",
     "ViltForImageAndTextRetrieval",