Implement v4 endpoints for OAuth (#6040)

* Implement POST /oauth/apps endpoint for APIv4

* Implement GET /oauth/apps endpoint for APIv4

* Implement GET /oauth/apps/{app_id} and /oauth/apps/{app_id}/info endpoints for APIv4

* Refactor API version independent oauth endpoints

* Implement DELETE /oauth/apps/{app_id} endpoint for APIv4

* Implement /oauth/apps/{app_id}/regen_secret endpoint for APIv4

* Implement GET /user/{user_id}/oauth/apps/authorized endpoint for APIv4

* Implement POST /oauth/deauthorize endpoint

model/oauth.go

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"net/http"
 	"unicode/utf8"
 )
 
@@ -36,50 +37,50 @@ type OAuthApp struct {
 func (a *OAuthApp) IsValid() *AppError {
 
 	if len(a.Id) != 26 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.app_id.app_error", nil, "")
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.app_id.app_error", nil, "", http.StatusBadRequest)
 	}
 
 	if a.CreateAt == 0 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.create_at.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.create_at.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	if a.UpdateAt == 0 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.update_at.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.update_at.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	if len(a.CreatorId) != 26 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.creator_id.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.creator_id.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	if len(a.ClientSecret) == 0 || len(a.ClientSecret) > 128 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.client_secret.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.client_secret.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	if len(a.Name) == 0 || len(a.Name) > 64 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.name.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.name.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	if len(a.CallbackUrls) == 0 || len(fmt.Sprintf("%s", a.CallbackUrls)) > 1024 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.callback.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.callback.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	for _, callback := range a.CallbackUrls {
 		if !IsValidHttpUrl(callback) {
-			return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.callback.app_error", nil, "")
+			return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.callback.app_error", nil, "", http.StatusBadRequest)
 		}
 	}
 
 	if len(a.Homepage) == 0 || len(a.Homepage) > 256 || !IsValidHttpUrl(a.Homepage) {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.homepage.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.homepage.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	if utf8.RuneCountInString(a.Description) > 512 {
-		return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.description.app_error", nil, "app_id="+a.Id)
+		return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.description.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 	}
 
 	if len(a.IconURL) > 0 {
 		if len(a.IconURL) > 512 || !IsValidHttpUrl(a.IconURL) {
-			return NewLocAppError("OAuthApp.IsValid", "model.oauth.is_valid.icon_url.app_error", nil, "app_id="+a.Id)
+			return NewAppError("OAuthApp.IsValid", "model.oauth.is_valid.icon_url.app_error", nil, "app_id="+a.Id, http.StatusBadRequest)
 		}
 	}