introduce beforeScenario hook

[ptrthomas]

at the very least for mocks, to complement the already existing configure afterScenario option: https://github.com/karatelabs/karate/tree/master/karate-netty#configure-afterscenario

this is needed because the Background in mocks is only "one time": https://github.com/karatelabs/karate/tree/master/karate-netty#background

teams will be able to do advanced request validation with mocks

note that the new JS mocks gives you this flexibility: https://github.com/karatelabs/karate/wiki/Karate-JavaScript-Mocks

but some teams prefer the simpler karate-style mocks

[ericdriggs]

You read my mind! Was just about to open this issue.
This would allow me to use a global coinfig to log scenario names before execution.
Especially useful for when scenarios are timing out.

[ptrthomas]

@ericdriggs cool. do note that this should be already possible via the ExecutionHook: https://github.com/karatelabs/karate/wiki/1.0-upgrade-guide#hooks