Add more translatable strings

[rene-coty]

Some items of the UI can't be translated such as : the type of the clipboard's content (e.g.: "file", "code", "link", "text") and the indicator that shows when the content has been copied to the clipboard (e.g.: "1 hour ago"). As they are not translatable, these strings will only appear in English, which can be confusing when the rest of the app has been localized See screenshot below

[oae]

I have added translation strings for titles and used already translated date-related strings.