Add Go echo server codegen (#9224)

* Update codegen config

* Add templates for Go Echo openapi-codegen

* Add the yaml config file!

* Add GoEchoServerCodegen.java.
This is the first iteration, it works but probably needs a lot of improvements.

* Update codegen, adds some comments.

* Update GoEchoServerCodegen.java

* Update GoEchoServerCodegen.java

* Update GoEchoServerCodegen.java and related yaml file

* Add the result of generate-samples.sh for CI purposes.

* Add the result of bin/utils/ensure-up-to-date for CI purposes.

* Update go-echo-server-petstore-new.yaml
Fix the outputdir

* Update in regard to result of ./bin/generate-samples.sh

* Update in regard to result of ./bin/generate-samples.sh

* Remove wrongly generated files

* Add correct generated files.

* Add changes regarding /bin/utils/ensure-up-to-date

* Update templates to include comments.

* Update/add result of ./bin/generate-samples.sh and ./bin/utils/export_docs_generators.sh

samples/server/petstore/go-echo-server/main.go

@@ -0,0 +1,83 @@
+package main
+
+import (
+	"github.com/GIT_USER_ID/GIT_REPO_ID/handlers"
+	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
+)
+
+func main() {
+	e := echo.New()
+
+    //todo: handle the error!
+	c, _ := handlers.NewContainer()
+
+	// Middleware
+	e.Use(middleware.Logger())
+	e.Use(middleware.Recover())
+	
+
+    // AddPet - Add a new pet to the store
+	e.POST("/v2/pet", c.AddPet)
+
+    // DeletePet - Deletes a pet
+	e.DELETE("/v2/pet/:petId", c.DeletePet)
+
+    // FindPetsByStatus - Finds Pets by status
+	e.GET("/v2/pet/findByStatus", c.FindPetsByStatus)
+
+    // FindPetsByTags - Finds Pets by tags
+	e.GET("/v2/pet/findByTags", c.FindPetsByTags)
+
+    // GetPetById - Find pet by ID
+	e.GET("/v2/pet/:petId", c.GetPetById)
+
+    // UpdatePet - Update an existing pet
+	e.PUT("/v2/pet", c.UpdatePet)
+
+    // UpdatePetWithForm - Updates a pet in the store with form data
+	e.POST("/v2/pet/:petId", c.UpdatePetWithForm)
+
+    // UploadFile - uploads an image
+	e.POST("/v2/pet/:petId/uploadImage", c.UploadFile)
+
+    // DeleteOrder - Delete purchase order by ID
+	e.DELETE("/v2/store/order/:orderId", c.DeleteOrder)
+
+    // GetInventory - Returns pet inventories by status
+	e.GET("/v2/store/inventory", c.GetInventory)
+
+    // GetOrderById - Find purchase order by ID
+	e.GET("/v2/store/order/:orderId", c.GetOrderById)
+
+    // PlaceOrder - Place an order for a pet
+	e.POST("/v2/store/order", c.PlaceOrder)
+
+    // CreateUser - Create user
+	e.POST("/v2/user", c.CreateUser)
+
+    // CreateUsersWithArrayInput - Creates list of users with given input array
+	e.POST("/v2/user/createWithArray", c.CreateUsersWithArrayInput)
+
+    // CreateUsersWithListInput - Creates list of users with given input array
+	e.POST("/v2/user/createWithList", c.CreateUsersWithListInput)
+
+    // DeleteUser - Delete user
+	e.DELETE("/v2/user/:username", c.DeleteUser)
+
+    // GetUserByName - Get user by user name
+	e.GET("/v2/user/:username", c.GetUserByName)
+
+    // LoginUser - Logs user into the system
+	e.GET("/v2/user/login", c.LoginUser)
+
+    // LogoutUser - Logs out current logged in user session
+	e.GET("/v2/user/logout", c.LogoutUser)
+
+    // UpdateUser - Updated user
+	e.PUT("/v2/user/:username", c.UpdateUser)
+
+
+	// Start server
+	e.Logger.Fatal(e.Start(":8080"))
+}