* Introduce EventBroker and RequestBroker as decoupling helpers that represent reactive (event-driven) and proactive (request/response) patterns without tight coupling between modules
* Address copilot observation. error log if failed listener call exception, handling listener overuse - run out of IDs
* Address review observations: no exception to leak, listeners must raise no exception, adding listener now reports error with Result.
* Added MultiRequestBroker utility to collect results from many providers
* Support an arbitrary number of arguments for RequestBroker's request/provider signature
* MultiRequestBroker allows provider procs to throw exceptions, which will be handled during request processing.
* MultiRequestBroker supports one zero arg signature and/or multi arg signature
* test no exception leaks from RequestBroker and MultiRequestBroker
* Embed MultiRequestBroker tests into common
* EventBroker: removed all ...Broker typed public procs to simplify EventBroker interface, forger is renamed to dropListener
* Make Request's broker type private
* MultiRequestBroker: Use explicit returns in generated procs
* Updated descriptions of EventBroker and RequestBroker, updated RequestBroker.setProvider, returns error if already set.
* Better description for MultiRequestBroker and its usage
* Add EventBroker support for ref objects, fix emit variant with event object ctor
* Add RequestBroker support for ref objects
* Add MultiRequestBroker support for ref objects
* Mover brokers under waku/common
