[MIEB] Add code for GME models

[izhx]

GME: Improving Universal Multimodal Retrieval by Multimodal LLMs
https://arxiv.org/pdf/2412.16855

Checklist

• Run tests locally to make sure nothing is broken using make test.
• Run the formatter to format the code using make lint.

Adding a model checklist

• I have filled out the ModelMeta object to the extent possible
• I have ensured that my model can be loaded using
  • mteb.get_model(model_name, revision) and
  • mteb.get_model_meta(model_name, revision)
• I have tested the implementation works on a representative set of tasks.