Separate similar error messages' translations for different rules

[arogachev]

Extracted from #514 (comment).

Related: #525.

Problem: changing translation for incorrect type message might affect multiple rules.
Possible solution: use keys for translation instead, something like "json.incorrectInputMessage".

This can be helpful when a user wants to hide technical details with broader messages for example.

[vjik]

Is there an example of a translation with a similar problem?

Usage keys added new dependency yiisoft/translator-message-php.