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/audio.go

@@ -0,0 +1,67 @@
+package object // import "github.com/SevereCloud/vksdk/v2/object"
+
+import (
+	"fmt"
+)
+
+// AudioAudio struct.
+type AudioAudio struct {
+	AccessKey           string             `json:"access_key"` // Access key for the audio
+	ID                  int                `json:"id"`
+	OwnerID             int                `json:"owner_id"`
+	Artist              string             `json:"artist"`
+	Title               string             `json:"title"`
+	Duration            int                `json:"duration"`
+	Date                int                `json:"date"`
+	URL                 string             `json:"url"`
+	IsHq                BaseBoolInt        `json:"is_hq"`
+	IsExplicit          BaseBoolInt        `json:"is_explicit"`
+	StoriesAllowed      BaseBoolInt        `json:"stories_allowed"`
+	ShortVideosAllowed  BaseBoolInt        `json:"short_videos_allowed"`
+	IsFocusTrack        BaseBoolInt        `json:"is_focus_track"`
+	IsLicensed          BaseBoolInt        `json:"is_licensed"`
+	StoriesCoverAllowed BaseBoolInt        `json:"stories_cover_allowed"`
+	LyricsID            int                `json:"lyrics_id"`
+	AlbumID             int                `json:"album_id"`
+	GenreID             int                `json:"genre_id"`
+	TrackCode           string             `json:"track_code"`
+	NoSearch            int                `json:"no_search"`
+	MainArtists         []AudioAudioArtist `json:"main_artists"`
+	Ads                 AudioAds           `json:"ads"`
+	Subtitle            string             `json:"subtitle"`
+}
+
+// ToAttachment return attachment format.
+func (audio AudioAudio) ToAttachment() string {
+	return fmt.Sprintf("audio%d_%d", audio.OwnerID, audio.ID)
+}
+
+// AudioAds struct.
+type AudioAds struct {
+	ContentID      string `json:"content_id"`
+	Duration       string `json:"duration"`
+	AccountAgeType string `json:"account_age_type"`
+	PUID1          string `json:"puid1"`
+	PUID22         string `json:"puid22"`
+}
+
+// AudioAudioArtist struct.
+type AudioAudioArtist struct {
+	Name   string `json:"name"`
+	ID     string `json:"id"`
+	Domain string `json:"domain"`
+}
+
+// AudioAudioUploadResponse struct.
+type AudioAudioUploadResponse struct {
+	Audio    string `json:"audio"`
+	Hash     string `json:"hash"`
+	Redirect string `json:"redirect"`
+	Server   int    `json:"server"`
+}
+
+// AudioLyrics struct.
+type AudioLyrics struct {
+	LyricsID int    `json:"lyrics_id"`
+	Text     string `json:"text"`
+}