Add a list of per-request usage data to Usage

[seratch]

Python SDK now has a list of per-request usage data in a Usage object. This TS SDK will have the same in future versions.

References:

• Add a list of per-request usage data to Usage openai-agents-python#1994
• feat: #1994 Add a list of per-request usage data to Usage  openai-agents-python#1995