Can't set init parameters for Filters

[Trygve Laugstøl]

addServlet returns a special builder for servlets (ServletHolderBuilder), but addFilter just returns the ServletContextHandlerBuilder.

Workaround:

    FilterHolder filterHolder = new FilterHolder(ServletContainer.class);
    filterHolder.setInitParameter("javax.ws.rs.Application", Jsr311Application.class.getCanonicalName());
    context.
            addFilterHolder(filterHolder, "/*", EnumSet.of(REQUEST)).