Add MetricValue that returns the max during aggregation

### Is your feature request related to a problem or challenge?

We have a scenario where we are performing multiple operations in parallel and are only interested in the one that takes the longest. Currently, `MetricValue::Time` is always summed on aggregation.

### Describe the solution you'd like

A new type, `MetricValue::MaxTime`, is implemented that functions the same as `MetricValue::Time` except on aggregation, it returns the max of the two times rather than the sum.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_