[OV] Update optimization docs page with information about VLMs

[nikita-savelyevv]

What does this PR do?

Changes to export and optimization optimum-intel openvino docs:

• Optimization https://moon-ci-docs.huggingface.co/docs/optimum-intel/pr_1007/en/openvino/optimization
  • Export to int8 with OVWeightQuantizationConfig(bits=8) instead of load_in_8bit=True.
  • Added examples for exporting VLMs with compression
  • Fixed command for data-aware compression
  • Added a mention of GPTQ algorithm, adopted example accoridingly
• Export https://moon-ci-docs.huggingface.co/docs/optimum-intel/pr_1007/en/openvino/export
  • Updated help info for optimum-cli export openvino command
  • Added examples for exporting with int4 & int4 data-aware compressin
  • Added an example for exporting SD with HQ

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests?

[HuggingFaceDocBuilderDev]

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