MVC and Webflux share some common business logic
so it makes sense to put them in the same module.
Also simplifies the MVC code, removing the custom argument
and return value handlers.
Weed out unecessary method param
Unignore some tests
The web module doesn't really need to depend on tomcat and all of
the Spring Boot web stack, but users need a way to grab that stuff
quickly if they want it (hence the new starter).
Also removed all spring-boot-starter dependencies from core and
context modules.