graph: backend: dnnl: backend refactor of adding fusion info attr

[xiang1guo]

Background

Preliminary work for MFDNN-13442. The main purpose of this PR is to bind the fusion_info as an attribute directly onto the op, rather than using a fusion_info_key to reference a container(currently a vector store in fusion_info_mgr) that manages the fusion info.

Works

• [x] Add new fusion_info attr.
• [x] Update all op's attr with new attr
• [x] Gtest update
• [x] rename fusion_info_mgr_t to reflect the updated function