Fix loading CLIPVisionConfig and CLIPTextConfig
# What does this PR do?

As described in #16185, there's a bug when loading `CLIPVisionModel` from a `CLIPModel` checkpoint. This is because the 
`CLIPVisionConfig` is not loaded correctly. And all the arguments use default values which correspond to the `openai/clip-vit-base-patch32` model, which results in shape mismatch when loading vision/text model from other CLIP checkpoints.

This PR override the `from_pretrained` methods for `CLIPVisionConfig` and `CLIPTextConfig` to allow loading from `CLIPConfig`.


Fixes #16185
_The documentation is not available anymore as the PR was closed or merged._