Add AutoBackbone + ResNetBackbone (#20229)

* Add ResNetBackbone

* Define channels and strides as property

* Remove file

* Add test for backbone

* Update BackboneOutput class

* Remove strides property

* Fix docstring

* Add backbones to SHOULD_HAVE_THEIR_OWN_PAGE

* Fix auto mapping name

* Add sanity check for out_features

* Set stage names based on depths

* Update to tuple

Co-authored-by: Niels Rogge <nielsrogge@Nielss-MacBook-Pro.local>

utils/check_repo.py

@@ -47,6 +47,7 @@ PRIVATE_MODELS = [
 # Being in this list is an exception and should **not** be the rule.
 IGNORE_NON_TESTED = PRIVATE_MODELS.copy() + [
     # models to ignore for not tested
+    "ResNetBackbone",  # Backbones have their own tests.
     "CLIPSegDecoder",  # Building part of bigger (tested) model.
     "TableTransformerEncoder",  # Building part of bigger (tested) model.
     "TableTransformerDecoder",  # Building part of bigger (tested) model.
@@ -668,6 +669,8 @@ SHOULD_HAVE_THEIR_OWN_PAGE = [
     "PyTorchBenchmarkArguments",
     "TensorFlowBenchmark",
     "TensorFlowBenchmarkArguments",
+    "ResNetBackbone",
+    "AutoBackbone",
 ]