[onert] Introduce Attention operator

[glistening]

It introduces Attention operator, which represents LlamaAttention or Standard Attention.
For former, it will include RoPE and for latter, it will do the original Transformer paper.

You can obtain decode.circle containing Attention using TICO:

• [test+operators] Fuse llama attention to circle attention TICO#217

[hseok-oh]

(It is not this draft's issue)
May be better to use naming rotate_half and rotate_every_two instead of model name GPT-NeoX and GPT-J.

GPT-NeoX: https://github.com/huggingface/transformers/blob/fe3c8ab1af558b95f67f5fafc0c55f09fd2b09db/src/transformers/models/gpt_neox/modeling_gpt_neox.py#L368
GPT-J: https://github.com/huggingface/transformers/blob/fe3c8ab1af558b95f67f5fafc0c55f09fd2b09db/src/transformers/models/gptj/modeling_gptj.py#L69
Llama: https://github.com/huggingface/transformers/blob/fe3c8ab1af558b95f67f5fafc0c55f09fd2b09db/src/transformers/models/llama/modeling_llama.py#L173

And it also may be Attention's parameter.

[glistening]

I am already get used the name of neox, which used rotate_half approach first. means neox-style. The name is also used in llama.cpp. But if rotate_half looks more readable, it is good to rename.

[glistening]

• rebased (as circle_schema.fbs is changed and bcqunembedding was introduced).
• layer_idx is removed.