cleanup client/selector/lookup (#1937)

* cleanup client/selector/lookup

* add mdns router, remove registry from client

* fix roundtripper

* remove comment

* fix compile issue

* fix mucp test

* fix api router

selector/options.go

@@ -1,31 +1,17 @@
 package selector
 
-import "github.com/micro/go-micro/v3/router"
-
 // Options used to configure a selector
 type Options struct{}
 
 // Option updates the options
 type Option func(*Options)
 
-// Filter the routes
-type Filter func([]router.Route) []router.Route
-
 // SelectOptions used to configure selection
-type SelectOptions struct {
-	Filters []Filter
-}
+type SelectOptions struct{}
 
 // SelectOption updates the select options
 type SelectOption func(*SelectOptions)
 
-// WithFilter adds a filter to the options
-func WithFilter(f Filter) SelectOption {
-	return func(o *SelectOptions) {
-		o.Filters = append(o.Filters, f)
-	}
-}
-
 // NewSelectOptions parses select options
 func NewSelectOptions(opts ...SelectOption) SelectOptions {
 	var options SelectOptions
@@ -33,9 +19,5 @@ func NewSelectOptions(opts ...SelectOption) SelectOptions {
 		o(&options)
 	}
 
-	if options.Filters == nil {
-		options.Filters = make([]Filter, 0)
-	}
-
 	return options
 }