Feature/cctv stub

[kulakoff]

Added processing of video streams sent to the client.

update server config, add real stub url for your media server

"stub": {
                "payment_require_url": "https://video.server.hostname:8443/stub_payment_require",
                "service_url": "https://video.server.hostname:8443/stub_service",
                "fallback_url": "https://video.server.hostname:8443/fallback"
            }

• flat is blocked - replace stream to stub "payment_require". example:

• IP camera is disabled in the admin panel - replace stream to stub "service" example:

• DVR stream is specified incorrectly - replace stream to stub "fallback". User made a mistake when adding the url or this field is empty. example: