Unify ops duration throttle to use throttle.json

Both the gas throttle and the ops duration throttles are one off implementation that do not take advantage of the infrastructure that exists for throttles created via the `throttles.json` file.

Explore the possibility of converting the ops duration throttle into a throttle that conforms to the throttles defined via `throttles.json`

Start by comparing the gas and ops duration throttles with the throttle definitions and infrastructure described by throttles.json. Determine whether the ops duration throttle can conform to that existing model, and consider the work done only when the conversion approach is established and the throttle uses the shared infrastructure.

Written by the indexing model from the issue text.