[IDEA-367321] Find new custom handlers on recursive dependency discovery

[aromaa]

The GradleOrderEnumeratorHandler would not be present in the root module as its not managed by Gradle. When the Gradle dependency is visited, we begin to recursively add its dependencies and pass in the old set of handlers from the original module. This leads to Gradle specific behavior not lighting up and resulting to incomplete classpath.

Fixes this by discovering the new set of handlers before we start recursively adding the dependencies.