Add an ability to use host-based routing instead of path-based for k8s infra

[sleshchenko]

Description

Many applications expect to be the only one application deployed on a host. And they may use absolute links. In case of using path-based routing, such applications will be broken.
An example of it is che-samples/web-java-spring.
There is the main page that redirects users to spring/hello page. But in case of host-based routing, it doesn't work.

See screencase how it works

So it is needed to investigate host-based routing for k8s-infra and add it as an option or replace current path-based routing.

[ghost]

This makes dev flow on k8s almost impossible

[skabashnyuk]

@eivantsov what do you mean?

[riuvshin]

@skabashnyuk have you seen attached screencast? it is not possible to access your application started in a WS to check your changes and even debug it.

[skabashnyuk]

@riuvshin understood

[ghost]

Looks like @guydaichs's PR fixes this one. Worked for me