Auth: Refactor auth package (#58920)

* Auth: move interface to its own file

* Auth: move to test package

* Auth: move quota consts to auth file

* Auth: move service to impl package

* Auth: move interfaces and related models to auth package

* Auth: Create sub package and type alias to avoid circular dependency

pkg/models/usertoken/user_token.go

@@ -0,0 +1,26 @@
+package usertoken
+
+type TokenRevokedError struct {
+	UserID                int64
+	TokenID               int64
+	MaxConcurrentSessions int64
+}
+
+func (e *TokenRevokedError) Error() string { return "user token revoked" }
+
+// UserToken represents a user token
+type UserToken struct {
+	Id            int64
+	UserId        int64
+	AuthToken     string
+	PrevAuthToken string
+	UserAgent     string
+	ClientIp      string
+	AuthTokenSeen bool
+	SeenAt        int64
+	RotatedAt     int64
+	CreatedAt     int64
+	UpdatedAt     int64
+	RevokedAt     int64
+	UnhashedToken string
+}