cuda4dnn(resize, tests): allow two-input resize, fix test thresholds

[YashasSamaga]

Set thresholds for FP16 target:

• YOLOv4 test
• EfficientDet test

Disabled tests:

• tf2_prelu (assertion fails; related issue Prelu from Tensorflow.keras (assert m.total() == outCn) #17263)
• MatMul (not supported)

Fixed tests:

• Resize layer with two inputs where the second input gives the shape (introduced in FlowNet PR)

All tests pass now!

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under OpenCV (BSD) License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or other license that is incompatible with OpenCV
• The PR is proposed to proper branch
• There is reference to original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake

force_builders=Custom
buildworker:Custom=linux-4
build_image:Custom=ubuntu-cuda:18.04

[alalek]

Thank you!