Webshop app should be translatable in Crowdin

[sihma]

This also concerns other Frappe project (payments, and most others, except from HRMS)

While ERPNext is available for translation in Crowdin, the Webshop app strings aren't, which leaves out big translation gaps were if you have, let's say, a website in French with a webshop, the website is translated except for all webshop functionalities.

This brings situation where users provide translations in issues, like in #144.

The app shoud be available for translations and so do the other Frappe apps. What is missing to provide this?

Thanks!