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

gateway/bridgemap/bvk.go

@@ -0,0 +1,11 @@
+// +build !novk
+
+package bridgemap
+
+import (
+	bvk "github.com/42wim/matterbridge/bridge/vk"
+)
+
+func init() {
+	FullMap["vk"] = bvk.New
+}