[MIEB] Complete all model meta based on v2.0.0 schema

[isaac-chung]

Here are the missing fields that are present in v2.0.0 but absent in mieb:

    n_parameters: int | None = None # exists but not often filled out.
    max_tokens: float | None = None # exists but not often filled out.
    embed_dim: int | None = None # exists but not often filled out.
    license: str | None = None
    open_weights: bool | None = None      # exists as `open_source`
    public_training_data: bool | None = None # exists but not often filled out.
    public_training_code: bool | None = None # exists but not often filled out.
    framework: list[FRAMEWORKS] = []    # exists but not often filled out.
    reference: STR_URL | None = None # exists but not often filled out.
    similarity_fn_name: DISTANCE_METRICS | None = None
    use_instructions: bool | None = None
    training_datasets: dict[str, list[str]] | None = None
    adapted_from: str | None = None
    superseded_by: str | None = None
    citation: str | None = None

Here are the missing fields that are present in mieb but absent in v2.0.0:

    modalities: list[MODALITIES] = ["text"]