Allow to autotranslate catalog

[AndreiMaz]

This option could be helpful for stores with multiple languages configured. In this case localizable entities (e.g. products, topics, categories, manufactures, etc) could be automatically translated by a store owners.

Add a new button "Pre-translate" to each entity details page. There will be a popup window allowing to choose (checkboxes) which properties to translate (e.g. product name, short description, full description). Once clicked it'll translate entered value ("standard" tab) and fill pre-translated values into tabs with localization. But a store owner will have to click the "Save" button in order to save the changes (let's add this hint to the pop-up window).

Let's make it configurable.

TODO: choose a library for translations. Maybe, we could implement several ones (similar to crowdin). In this it should be implemented vi plugin system