* add HasStopNext to State which exposes an API to stop the fuzzer. Stops the fuzzer in fuzz_loop or
fuzz_loop_for when set to true
* fix import
* rename HasStopNext to HasShouldStopFuzzing and stop_next to should_stop_fuzzing
* added HasShouldStopFuzzing trait constraint for libafl_libfuzzer_runtime fuzzer
* rename HasShouldStopFuzzing to Stoppable and add it as a type constraint in libafl_libfuzzer report.rs
* rename should_stop_fuzzing -> should_stop
* introduce Event::Stop
* fix prelude import
* Call send_exiting when processing Event::Stop in restartable managers
* fix clippy
* introduce on_shutdown function in EventProcessor, a function to exit
without saving state gracefully. In contrast with on_restart.
* call manager.on_shutdown when stopping in fuzz_loop due to state.should_stop
* Add missing on_shutdown implementations
Check after every stage in Stages::perform_all if should exit and do so.
* remove specialization
* fix doc
* introduce EventProcessor constraint in libafl_libfuzzer_runtime
run clippy in libafl_libfuzzer_runtime
* fix CentralizedEventManager's on_shutdown not calling inner.on_shutdown
* fix bugs in CentralizedLauncher that wouldn't allow children to terminate properly
* don't call send_exiting when processing Event::Stop since it will be called when calling on_shutdown anyways
* clippy
* add set_exit_after so broker does not need to inner_mut to set exit_cleanly_after
* return Cow<str> from Event::name_detailed instead of a String
* fix missing import in libafl_libfuzzer_runtime
* add initate_stop and reset_stop to Stoppable trait to superceed should_stop_mut
* clippy
* typo
* rename initate_stop to request_stop, should_stop to stop_requested and reset_stop to discard_stop_request
* fix missing import
* windows clippy fix
* fix broker typo
