backend should send telegram notifications

[zavelevsky]

The general approach is that carbon backend will also harvest Vortex and Fastlane events - and send the telegram notifications.
This will allow our instance, once configured to cover all supported chains, to send notifications for our needs - and potentially also to paying customers. Licensees can of course utilize this capability themselves after pulling the latest code.

At phase 1, which will take 1-2 days, Yariv will evaluate the answers to a key questions:
What's the expected rate of notifications and whether it will require a queuing system that will require more work and proficiency from licensees. He will also try to keep it simple, because of this motivation, maybe by finding a cheap service that can take care of it.

Then, we will make the necessary decisions and move forward with the implementation that will likely take several more days - but it's not a huge task.

So milestones:

1. planning - 1-2 days
2. code is ready (can be used by licensees) - 4-7 days
3. our backend covers all chains - 1-2 days (with shady USD prices)

Current state:

Relying both on 3rd party and Nick’s code. The 3rd party is terminating their service and Nick’s code is not production ready.

reported events:

• carbon events, vortex events, fastlane, bancor pools (withdrawal, closure), BNT burn -> those will are outside the scope of this issue
• Enriched with external price data
• Enriched with token decimal/symbol data
• Sometimes, enriched with information that is out of the specific event we listen to