Improve the UX of the translation asset editor

[aabounegm]

When creating a new translation, after tapping on a message to translate, it shows a list with one empty item under "Accepted translations" by default, which is not very understandable to the users. It also doesn't make sense for the accepted translation to be a list when only one translation will be used in the stories.

To make it more intuitive:

• Change the "Accepted translations" from a list to a simple text element
• Display "No accepted translation yet" in italics instead of an empty list
• Rename "pending translations" to "suggested translations"
• Autofocus the "suggest translation" input

I understand that "pending" is supposed to be different than "suggested", and that there can be multiple accepted ones with one of them being currently active, but this distinction is not important to the end-user. Any translation suggestion (whether "approved" or not) goes under "Suggested translations", and only the active one is displayed under "Accepted translation"