Remove legacy code (#3838)

* Add feature migration notice

* Remove legacy code of transport processing

* Clear legacy proto field

* Fix missing

* Unify protocolname

* Test remove

* Supressor

* Weird code

* Remove errorgen related comments

main/commands/all/commands.go

@@ -7,8 +7,6 @@ import (
 	"github.com/xtls/xray-core/main/commands/base"
 )
 
-// go:generate go run github.com/xtls/xray-core/common/errors/errorgen
-
 func init() {
 	base.RootCommand.Commands = append(
 		base.RootCommand.Commands,