Add /set_working_hours and some bugfixes

[examplefirstaccount]

Issues

• closes #44
• closes #45
• closes #46

Details

Bugfixes:

• Fixed serious bug connected to topics handling. Because of strange decision of tg API developers, in General topic and in supergroup w/o topics attribute message_thread_id of reply message was not null, but the id of message it replied. Because of that commands that require replies didn't work in General topic and supergroup w/o topics.
• Fixed issues connected to command menu updating after launching the bot
• Fixed messages of meeting arrangements, now it shows workdays from schedule
• Fixed reminders scheduling, now they are sent by schedule
• Fixed bug connected to /get_chat_state command. TG API just not sent the message if chat state was too long.
• Fixed bug when bot sent reminders to deleted messages

[deemp]

@examplefirstaccount multiple strings aren't babel-friendly. Wrap them into _(..) and use .format. Where necessary, use multi-line strings with dedent on wrapped strings.

UPD: there are only a few of them. Will fix them on my own.