Function try_variable_width_miniblock_with_generic_offsets 

pub fn try_variable_width_miniblock_with_generic_offsets(
    field: &Field,
    data: &DataBlock,
    params: &CompressionFieldParams,
) -> Result<Option<Box<dyn MiniBlockCompressor>>>

Encode variable-width miniblocks whose offset chunks may use generic block codecs.

Only the unstable Lance 2.3 compression strategy may select this grammar. Stable 2.1/2.2 strategies must use try_variable_width_miniblock.