Check number of special characters on translation

[rougeth]

To increase safety when translating string from the bot, we could warn the user if the translation contains more or less special characters than the source string. Usually the number of special characters shouldn’t change.

Example of source string:

Close the ``ndbm`` database.

Translation:

Fecha o banco de dados `ndbm`.

In the example above, the bot should warn the user that its translation contains less special characters than the source string.