Register swagger API (#7246)

* init

* Fix statik gen

* Fix swagger

* Change swagger url

* Fix swagger serve

* remove ibc swagger from legacy docs

* Add old routes config

* Move swagger api to app.go

* add godoc

* Fix inputs

* Fix swagger dir

* Fix statik

* refactor

* fmt

* fix doc

* Fix swagger config check

client/docs/config.json

@@ -1,10 +1,17 @@
 {
   "swagger": "2.0",
   "info": {
-    "title": "Cosmos SDK - GRPC Gateway",
+    "title": "Cosmos SDK - Legacy REST and gRPC Gateway docs",
+    "description": "A REST interface for state queries, legacy transactions",
     "version": "1.0.0"
   },
   "apis": [
+    {
+      "url": "./client/docs/swagger_legacy.yaml",
+      "dereference": {
+        "circular": "ignore"
+      }
+    },
     {
       "url": "./cosmos/auth/v1beta1/query.swagger.json",
       "operationIds": {