[Reload] small rework

[Aluerie]

I'm not sure if the end-design gonna end up as ToDo list follows but:

• $reload pull
  analogy to RDanny's reload all ; the idea here is that instead of GitAction to restart the bot and thus erase all cache we just pull and reload only those extensions that got changed.
• $reload category
  currently we can only reload sections as in $reload fpc.dota. But it would be to be able to do $reload fpc as well. We probably can just do some get_extensions analogy here, looping over folder.
• $reload modules
  reload not only extensions, but also modules for quicker "restart" the bot than fully from the sctrach.