Fix a bunch of issues

[Martoon-00]

Clarification and motivation

I posted a few issues in this Notion document, let's resolve them under this ticket.

Acceptance criteria

• All the mentioned issues are discussed and resolved.

[YuriRomanowski]

Each message of bot ends with “Something wrong?” and a button

Indeed, we can just remove it. Instead, we can attempt to give a hint how to use the entrypoints. For example, we can handle /tzhelp command and repond with an ephemeral containing help message that contains all the information about how the bot works and what are available entrypoints. But the user should also notice the command existense somehow, and this is what we can write in a simple ephemeral containing the translations. For it not to be too annoying, we can append this not to every ephemeral but for example with 0.1 chance (or less).