Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/playbooks/client/error_response.go

@@ -0,0 +1,52 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package client
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+)
+
+// ErrorResponse is an error from an API request.
+type ErrorResponse struct {
+	// Method is the HTTP verb used in the API request.
+	Method string
+	// URL is the HTTP endpoint used in the API request.
+	URL string
+	// StatusCode is the HTTP status code returned by the API.
+	StatusCode int
+
+	// Err is the error parsed from the API response.
+	Err error `json:"error"`
+}
+
+func (e *ErrorResponse) UnmarshalJSON(data []byte) error {
+	type Alias ErrorResponse
+	temp := &struct {
+		Err string `json:"error"`
+		*Alias
+	}{
+		Alias: (*Alias)(e),
+	}
+
+	// Try to extract a structured error from the body, otherwise fall back to using
+	// the whole body as the error message.
+	if err := json.Unmarshal(data, &temp); err != nil || temp.Err == "" {
+		e.Err = errors.New(string(data))
+	} else {
+		e.Err = errors.New(temp.Err)
+	}
+	return nil
+}
+
+// Unwrap exposes the underlying error of an ErrorResponse.
+func (e *ErrorResponse) Unwrap() error {
+	return e.Err
+}
+
+// Error describes the error from the API request.
+func (e *ErrorResponse) Error() string {
+	return fmt.Sprintf("%s %s [%d]: %v", e.Method, e.URL, e.StatusCode, e.Err)
+}