Add efficiency metrics to the benchmarking code

[neubig]

• tokens
• steps
• number of tool calls
• wall clock

[lintangsutawika]

Discussion with Xuhui: number of tool calls -> Avg Number of Tool Calls per Step

[XuhuiZhou]

wall clock: the duration of a session.

[adityasoni9998]

Except for token cost/dollar cost, these have been implemented in evaluation code as well: OpenHands/benchmarks#141

[XuhuiZhou]

Oh good, didn't know. Is it more for evaluation? (like not used during training)

[XuhuiZhou]

@lintangsutawika I think we could close this issue as the relevant pull request is merged?

#33