Add vk bridge (#1372)

* Add vk bridge

* Vk bridge attachments

* Vk bridge forwarded messages

* Vk bridge sample config and code cleanup

* Vk bridge add vendor

* Vk bridge message edit

* Vk bridge: fix fetching names of other bots

* Vk bridge: code cleanup

* Vk bridge: fix shadows declaration

* Vk bridge: remove UseFileURL

vendor/github.com/SevereCloud/vksdk/v2/object/donut.go

@@ -0,0 +1,9 @@
+package object
+
+// DonutDonatorSubscriptionInfo struct.
+type DonutDonatorSubscriptionInfo struct {
+	OwnerID         int    `json:"owner_id"`
+	NextPaymentDate int    `json:"next_payment_date"`
+	Amount          int    `json:"amount"`
+	Status          string `json:"status"`
+}