Add support for inspecting exception causes in `@Retry`

Is your feature request related to a problem?

Sometimes the exception that you want to actually want to look at is the cause of the top-level exception. For example if the exception happened in a condition you get a ConditionFailedWithExceptionError which is fairly unspecific.

Describe the solution you'd like

Either always expect causes, or add a flag to inspect them when configured.

@Retry (
    exceptions = StaleElementReferenceException,
    inspectCauses = true
)

Describe alternatives you've considered

@Retry (
    exceptions = [StaleElementReferenceException, ConditionFailedWithExceptionError],
    // exceptions don't check causes, so we need to do it in the condition
    condition = {
        failure instanceof StaleElementReferenceException || failure.cause instanceof StaleElementReferenceException
    }
)

Additional context

No response

Start by locating the @Retry implementation and its existing exception-matching tests. Review how configured exceptions and ConditionFailedWithExceptionError are currently handled, then compare the requested inspectCauses option with the condition-based workaround. Done means the requested cause-inspection behavior is supported without requiring that workaround, while existing behavior remains intact.