feat(ml): add more search models

[mertalev]

Description

This PR adds a number of OpenCLIP search models that give very competitive results, especially considering their efficiency.

Also updates the code for exporting models to ONNX, mainly making the search models static and adding a line to ensure none of the ops are in training mode.

Monolingual:
ViT-B-16-SigLIP-256__webli
ViT-B-16-SigLIP-384__webli
ViT-B-16-SigLIP-512__webli
ViT-B-16-SigLIP__webli
ViT-L-16-SigLIP-256__webli
ViT-L-16-SigLIP-384__webli
ViT-SO400M-14-SigLIP-384__webli

This is how they stack up (models in red are new):

Source for recall@k scores, considering only image retrieval.

Multilingual:
ViT-B-16-SigLIP-i18n-256__webli
nllb-clip-base-siglip__mrl
nllb-clip-large-siglip__mrl

This is how they stack up (models in red are new):

Source for recall@k scores, considering only image retrieval.