[core] Initial FeatureSet structures and definitions (#3614)

[core] Initial FeatureSet structures and definitions
Add default feature set to DefaultCodegen
Initial FeatureSet definitions for:

*  ada 
*  android 
*  apache2 
*  asciidoc 
*  aspnetcore 
*  avro 
*  bash 
*  c 
*  clojure 
*  cpp-pistache-server 
*  cpp-qt5-client 
*  cpp-qt5-qhttpengine-server 
*  cpp-restbed-server 
*  cpp-restsdk 
*  cpp-tizen 
*  csharp 
*  csharp-nancyfx 
*  csharp-netcore 
*  cwiki 
*  dart 
*  eiffel 
*  elixir 
*  elm 
*  erlang 
*  flash 
*  fsharp-functions 
*  go  Client/Server
*  graphql-nodejs-express-server 
*  graphql-schema 
*  groovy 
*  haskell 
*  haskell-http-client 
*  java 
*  jmeter 
*  kotlin 
*  kotlin vertx 
*  kotlin-server 
*  kotlin-spring 
*  lua 
*  mysql 
*  nim 
*  nodejs 
*  nodejs-express 
*  objc 
*  ocaml 
*  openapi 
*  openapi-yaml 
*  perl 
*  php 
*  php-laravel 
*  php-lumen 
*  php-silex 
*  php-slim 
*  php-symfony 
*  php-ze-ph 
*  powershell 
*  protobuf 
*  protobuf-schema 
*  python 
*  python-aiohttp 
*  python-blueplanet 
*  python-experimental 
*  r 
*  ror 
*  ruby 
*  ruby 
*  ruby-sinatra 
*  rust 
*  scala-akka 
*  scala-finch 
*  scala-gatling 
*  scala-http-client 
*  scala-lagom 
*  scala-play 
*  scalatra 
*  scalaz 
*  spring 
*  static docs 
*  swift 
*  typescript

samples/client/petstore/haskell-http-client/lib/OpenAPIPetstore/API/Fake.hs

@@ -277,9 +277,9 @@ instance Produces TestClientModel MimeJSON
 
 -- | @POST \/fake@
 -- 
--- Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
+-- Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
 -- 
--- Fake endpoint for testing various parameters 假端點 偽のエンドポイント 가짜 엔드 포인트 
+-- Fake endpoint for testing various parameters  假端點  偽のエンドポイント  가짜 엔드 포인트
 -- 
 -- AuthMethod: 'AuthBasicHttpBasicTest'
 -- 

samples/client/petstore/haskell-http-client/openapi.yaml

@@ -778,11 +778,11 @@ paths:
       - fake
       x-codegen-request-body-name: body
     post:
-      description: |
+      description: |-
         Fake endpoint for testing various parameters
-        假端點
-        偽のエンドポイント
-        가짜 엔드 포인트
+         假端點
+         偽のエンドポイント
+         가짜 엔드 포인트
       operationId: testEndpointParameters
       requestBody:
         content:
@@ -869,11 +869,11 @@ paths:
           description: User not found
       security:
       - http_basic_test: []
-      summary: |
+      summary: |-
         Fake endpoint for testing various parameters
-        假端點
-        偽のエンドポイント
-        가짜 엔드 포인트
+         假端點
+         偽のエンドポイント
+         가짜 엔드 포인트
       tags:
       - fake
   /fake/outer/number: