#147: add a web redirector service

[ForNeVeR]

Closes #147.

It turns out we were writing our database in a wrong way. When I send a photo, Telegram will usually send to bot a message with several PhotoSize objects of different sizes. All of them were written to the database, which I don't think is required.

Instead, we should deduplicate the PhotoSize objects based on the FileUniqueId, but there's another problem: Funogram version we use doesn't provide the access to this field at all.

So, I had to update Funogram and change quite a lot of code in our tests to make it work.

The above isn't true and FileUniqueId turned out to not be useful for this use case. Anyway, I've decided to update Funogram.

TODO:

• [x] unit tests
• [x] logging
• [x] fix issue with file unique id
• [x] deployment guide
• [x] review
• [x] figure out the TODOs
• [x] wait for https://github.com/Dolfik1/Funogram/issues/46
• [x] manual testing

[ForNeVeR]

One problem I am still struggling with is figuring out the FileUniqueId business.

For now, it seems Telegram sends us several different UniqueIds for each image send to Telegram, what the actual hell.