SPR-11825 SubPWSocketH: eventPublisher population

JIRA: https://jira.spring.io/browse/SPR-11825

There is no guaranty in order of `setters` invocations, even if they are container infrastructure,
e.g. `ApplicationEventPublisherAware` in case of `SubProtocolWebSocketHandler`

Provide 'double' `eventPublisher` population to `SubProtocolHandler`:
from `setApplicationEventPublisher` and `addProtocolHandler`

**Cherry-pick to 4.0.x**