Attempt to log the stack where cross-request promises are being resolved

[jasnell]

I don't think we want to keep this is forever ...

Since we don't have a way of testing log output yet in workerd it's difficult to test this reliably. Here's what the log output currently looks from the test (just a sampling)

...
workerd/server/server.c++:3851: debug: [ TEST ] cross-context-promise-test:asyncIterWorks
workerd/server/server.c++:3859: debug: [ PASS ] cross-context-promise-test:asyncIterWorks
workerd/server/server.c++:3851: debug: [ TEST ] cross-context-promise-test:crossContextRejectWorks
workerd/io/worker.c++:1213: warning: NOSENTRY Warning: Cross Request Promise Resolve
    at Object.reject (<anonymous>)
    at rejectTest (worker:238:23)
    at Object.fetch (worker:142:14)
workerd/server/server.c++:3859: debug: [ PASS ] cross-context-promise-test:crossContextRejectWorks
workerd/server/server.c++:3851: debug: [ TEST ] cross-context-promise-test:crossContextResolveWorks
workerd/io/worker.c++:1213: warning: NOSENTRY Warning: Cross Request Promise Resolve
    at Object.resolve (<anonymous>)
    at worker:200:44
    at resolveTest (worker:200:7)
    at Object.fetch (worker:140:14)
workerd/server/server.c++:3859: debug: [ PASS ] cross-context-promise-test:crossContextResolveWorks
workerd/server/server.c++:3851: debug: [ TEST ] cross-context-promise-test:crossContextStreamWorks
workerd/io/worker.c++:1213: warning: NOSENTRY Warning: Cross Request Promise Resolve
    at crossRequestStream (worker:268:32)
    at Object.fetch (worker:144:14)
workerd/server/server.c++:3859: debug: [ PASS ] cross-context-promise-test:crossContextStreamWorks
workerd/server/server.c++:3851: debug: [ TEST ] cross-context-promise-test:customThenableWorks
workerd/io/worker.c++:1213: warning: NOSENTRY Warning: Cross Request Promise Resolve
    at <anonymous>
    at Object.<anonymous> (worker:306:5)
    at Object.apply (node-internal:mock:411:28)
workerd/server/server.c++:3859: debug: [ PASS ] cross-context-promise-test:customThenableWorks
workerd/server/server.c++:3851: debug: [ TEST ] cross-context-promise-test:cyclicAwaitsWorks
...