Support benchmarking used `WeightV2` per contract call

Having benchmark metrics based on whole block metrics provides very useful insights about the overall performance of a contracts chain. However, to find and debug specific bottlenecks, we should be able to have more fine grained measurements.

Ideally, we'd use some off-chain engine like `drink` for that. This would make it very easy to integrate the benchmarks in ink! and Solang CI pipelines. 