ThirdPartyServices: SetContactMethods for setting, enable/disable

replace AddContactMethods with a more generalised SetContactMethods,
which can set (or leave alone) contact method addresses/names/ids and
set (or leave alone) contact preferences. A little awkward to use, but
works everywhere, and now a bunch of Jellyseerr integration features are
present for Ombi (which they should've been anyway).

models.go

@@ -278,7 +278,7 @@ type telegramSetDTO struct {
 	ID    string `json:"id"` // Jellyfin ID of user.
 }
 
-type SetContactMethodsDTO struct {
+type SetContactPreferencesDTO struct {
 	ID       string `json:"id"`
 	Email    bool   `json:"email"`
 	Discord  bool   `json:"discord"`