Add API Endpoint for Resending User Invitations in Auth0 (#989)

* add request handler for sending invite

* add InviteUser method to account manager interface

* add InviteUser mock

* add invite user endpoint to user handler

* add InviteUserByID to manager interface

* implement InviteUserByID in all idp managers

* resend user invitation

* add invite user handler tests

* refactor

* user userID for sending invitation

* fix typo

* refactor

* pass userId in url params

management/server/idp/idp.go

@@ -17,6 +17,7 @@ type Manager interface {
 	GetAllAccounts() (map[string][]*UserData, error)
 	CreateUser(email string, name string, accountID string) (*UserData, error)
 	GetUserByEmail(email string) ([]*UserData, error)
+	InviteUserByID(userID string) error
 }
 
 // ClientConfig defines common client configuration for all IdP manager