Thanks for the quick PR! Will have a closer look later today/on the weekend

• How to test for via_bot attribute of a Message

We're currently only testing answer_inline_query by mocking. But as setting the attribute is not our thing to do, but TGs, personally I'd say test manually and that's it.

• Do we want to offer the mime types of the InlineQueryResults thumb urls as constants? If yes, where?

Can you test, if TG servers infere that automatically? If yes: I don't really see a need for someone setting that manually and hence, for adding the corresponding constants

@Bibo-Joshi The docs say telegrams server automatically assume JPEG. I can test it if you want